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Gatus is a developer-oriented health dashboard that gives you the ability to monitor your services using HTTP, ICMP, TCP, and even DNS
queries as well as evaluate the result of said queries by using a list of conditions on values like the status code,
the response time, the certificate expiration, the body and many others. The icing on top is that each of these health
checks can be paired with alerting via Slack, Teams, PagerDuty, Discord, Twilio and many more.

I personally deploy it in my Kubernetes cluster and let it monitor the status of my
core applications: https://status.twin.sh/

_Looking for a managed solution? Check out [Gatus.io](https://gatus.io)._

<details>
  <summary><b>Quick start</b></summary>

```console
docker run -p 8080:8080 --name gatus twinproduction/gatus:stable
```
You can also use GitHub Container Registry if you prefer:
```console
docker run -p 8080:8080 --name gatus ghcr.io/twin/gatus:stable
```
For more details, see [Usage](#usage)
</details>

> ❤ Like this project? Please consider [sponsoring me](https://github.com/sponsors/TwiN).

![Gatus dashboard](.github/assets/dashboard-dark.png)

Have any feedback or questions? [Create a discussion](https://github.com/TwiN/gatus/discussions/new).


## Table of Contents
- [Table of Contents](#table-of-contents)
- [Why Gatus?](#why-gatus)
- [Features](#features)
- [Usage](#usage)
- [Configuration](#configuration)
  - [Endpoints](#endpoints)
  - [External Endpoints](#external-endpoints)
  - [Conditions](#conditions)
    - [Placeholders](#placeholders)
    - [Functions](#functions)
  - [Storage](#storage)
  - [Client configuration](#client-configuration)
  - [Alerting](#alerting)
    - [Configuring AWS SES alerts](#configuring-aws-ses-alerts)
    - [Configuring Discord alerts](#configuring-discord-alerts)
    - [Configuring Email alerts](#configuring-email-alerts)
    - [Configuring Gitea alerts](#configuring-gitea-alerts)
    - [Configuring GitHub alerts](#configuring-github-alerts)
    - [Configuring GitLab alerts](#configuring-gitlab-alerts)
    - [Configuring Google Chat alerts](#configuring-google-chat-alerts)
    - [Configuring Gotify alerts](#configuring-gotify-alerts)
    - [Configuring HomeAssistant alerts](#configuring-homeassistant-alerts)
    - [Configuring Ilert alerts](#configuring-ilert-alerts)
    - [Configuring Incident.io alerts](#configuring-incidentio-alerts)
    - [Configuring JetBrains Space alerts](#configuring-jetbrains-space-alerts)
    - [Configuring Matrix alerts](#configuring-matrix-alerts)
    - [Configuring Mattermost alerts](#configuring-mattermost-alerts)
    - [Configuring Messagebird alerts](#configuring-messagebird-alerts)
    - [Configuring Ntfy alerts](#configuring-ntfy-alerts)
    - [Configuring Opsgenie alerts](#configuring-opsgenie-alerts)
    - [Configuring PagerDuty alerts](#configuring-pagerduty-alerts)
    - [Configuring Pushover alerts](#configuring-pushover-alerts)
    - [Configuring Slack alerts](#configuring-slack-alerts)
    - [Configuring Teams alerts *(Deprecated)*](#configuring-teams-alerts-deprecated)
    - [Configuring Teams Workflow alerts](#configuring-teams-workflow-alerts)
    - [Configuring Telegram alerts](#configuring-telegram-alerts)
    - [Configuring Twilio alerts](#configuring-twilio-alerts)
    - [Configuring Zulip alerts](#configuring-zulip-alerts)
    - [Configuring custom alerts](#configuring-custom-alerts)
    - [Setting a default alert](#setting-a-default-alert)
  - [Maintenance](#maintenance)
  - [Security](#security)
    - [Basic Authentication](#basic-authentication)
    - [OIDC](#oidc)
  - [TLS Encryption](#tls-encryption)
  - [Metrics](#metrics)
    - [Custom Labels](#custom-labels)
  - [Connectivity](#connectivity)
  - [Remote instances (EXPERIMENTAL)](#remote-instances-experimental)
- [Deployment](#deployment)
  - [Docker](#docker)
  - [Helm Chart](#helm-chart)
  - [Terraform](#terraform)
- [Running the tests](#running-the-tests)
- [Using in Production](#using-in-production)
- [FAQ](#faq)
  - [Sending a GraphQL request](#sending-a-graphql-request)
  - [Recommended interval](#recommended-interval)
  - [Default timeouts](#default-timeouts)
  - [Monitoring a TCP endpoint](#monitoring-a-tcp-endpoint)
  - [Monitoring a UDP endpoint](#monitoring-a-udp-endpoint)
  - [Monitoring a SCTP endpoint](#monitoring-a-sctp-endpoint)
  - [Monitoring a WebSocket endpoint](#monitoring-a-websocket-endpoint)
  - [Monitoring an endpoint using ICMP](#monitoring-an-endpoint-using-icmp)
  - [Monitoring an endpoint using DNS queries](#monitoring-an-endpoint-using-dns-queries)
  - [Monitoring an endpoint using SSH](#monitoring-an-endpoint-using-ssh)
  - [Monitoring an endpoint using STARTTLS](#monitoring-an-endpoint-using-starttls)
  - [Monitoring an endpoint using TLS](#monitoring-an-endpoint-using-tls)
  - [Monitoring domain expiration](#monitoring-domain-expiration)
  - [disable-monitoring-lock](#disable-monitoring-lock)
  - [Reloading configuration on the fly](#reloading-configuration-on-the-fly)
  - [Endpoint groups](#endpoint-groups)
  - [Exposing Gatus on a custom path](#exposing-gatus-on-a-custom-path)
  - [Exposing Gatus on a custom port](#exposing-gatus-on-a-custom-port)
  - [Configuring a startup delay](#configuring-a-startup-delay)
  - [Keeping your configuration small](#keeping-your-configuration-small)
  - [Proxy client configuration](#proxy-client-configuration)
  - [How to fix 431 Request Header Fields Too Large error](#how-to-fix-431-request-header-fields-too-large-error)
  - [Badges](#badges)
    - [Uptime](#uptime)
    - [Health](#health)
    - [Health (Shields.io)](#health-shieldsio)
    - [Response time](#response-time)
    - [Response time (chart)](#response-time-chart)
      - [How to change the color thresholds of the response time badge](#how-to-change-the-color-thresholds-of-the-response-time-badge)
  - [API](#api)
    - [Interacting with the API programmatically](#interacting-with-the-api-programmatically)
    - [Raw Data](#raw-data)
      - [Uptime](#uptime-1)
      - [Response Time](#response-time-1)
  - [Installing as binary](#installing-as-binary)
  - [High level design overview](#high-level-design-overview)


## Why Gatus?
Before getting into the specifics, I want to address the most common question:
> Why would I use Gatus when I can just use Prometheus’ Alertmanager, Cloudwatch or even Splunk?

Neither of these can tell you that there’s a problem if there are no clients actively calling the endpoint.
In other words, it's because monitoring metrics mostly rely on existing traffic, which effectively means that unless
your clients are already experiencing a problem, you won't be notified.

Gatus, on the other hand, allows you to configure health checks for each of your features, which in turn allows it to
monitor these features and potentially alert you before any clients are impacted.

A sign you may want to look into Gatus is by simply asking yourself whether you'd receive an alert if your load balancer
was to go down right now. Will any of your existing alerts be triggered? Your metrics won’t report an increase in errors
if no traffic makes it to your applications. This puts you in a situation where your clients are the ones
that will notify you about the degradation of your services rather than you reassuring them that you're working on
fixing the issue before they even know about it.


## Features
The main features of Gatus are:

- **Highly flexible health check conditions**: While checking the response status may be enough for some use cases, Gatus goes much further and allows you to add conditions on the response time, the response body and even the IP address.
- **Ability to use Gatus for user acceptance tests**: Thanks to the point above, you can leverage this application to create automated user acceptance tests.
- **Very easy to configure**: Not only is the configuration designed to be as readable as possible, it's also extremely easy to add a new service or a new endpoint to monitor.
- **Alerting**: While having a pretty visual dashboard is useful to keep track of the state of your application(s), you probably don't want to stare at it all day. Thus, notifications via Slack, Mattermost, Messagebird, PagerDuty, Twilio, Google chat and Teams are supported out of the box with the ability to configure a custom alerting provider for any needs you might have, whether it be a different provider or a custom application that manages automated rollbacks.
- **Metrics**
- **Low resource consumption**: As with most Go applications, the resource footprint that this application requires is negligibly small.
- **[Badges](#badges)**: ![Uptime 7d](https://status.twin.sh/api/v1/endpoints/core_blog-external/uptimes/7d/badge.svg) ![Response time 24h](https://status.twin.sh/api/v1/endpoints/core_blog-external/response-times/24h/badge.svg)
- **Dark mode**

![Gatus dashboard conditions](.github/assets/dashboard-conditions.png)


## Usage

<details>
  <summary><b>Quick start</b></summary>

```console
docker run -p 8080:8080 --name gatus twinproduction/gatus
```
You can also use GitHub Container Registry if you prefer:
```console
docker run -p 8080:8080 --name gatus ghcr.io/twin/gatus
```
If you want to create your own configuration, see [Docker](#docker) for information on how to mount a configuration file.
</details>

Here's a simple example:
```yaml
endpoints:
  - name: website                 # Name of your endpoint, can be anything
    url: "https://twin.sh/health"
    interval: 5m                  # Duration to wait between every status check (default: 60s)
    conditions:
      - "[STATUS] == 200"         # Status must be 200
      - "[BODY].status == UP"     # The json path "$.status" must be equal to UP
      - "[RESPONSE_TIME] < 300"   # Response time must be under 300ms

  - name: make-sure-header-is-rendered
    url: "https://example.org/"
    interval: 60s
    conditions:
      - "[STATUS] == 200"                          # Status must be 200
      - "[BODY] == pat(*<h1>Example Domain</h1>*)" # Body must contain the specified header
```

This example would look similar to this:

![Simple example](.github/assets/example.png)

By default, the configuration file is expected to be at `config/config.yaml`.

You can specify a custom path by setting the `GATUS_CONFIG_PATH` environment variable.

If `GATUS_CONFIG_PATH` points to a directory, all `*.yaml` and `*.yml` files inside said directory and its
subdirectories are merged like so:
- All maps/objects are deep merged (i.e. you could define `alerting.slack` in one file and `alerting.pagerduty` in another file)
- All slices/arrays are appended (i.e. you can define `endpoints` in multiple files and each endpoint will be added to the final list of endpoints)
- Parameters with a primitive value (e.g. `metrics`, `alerting.slack.webhook-url`, etc.) may only be defined once to forcefully avoid any ambiguity
    - To clarify, this also means that you could not define `alerting.slack.webhook-url` in two files with different values. All files are merged into one before they are processed. This is by design.

> 💡 You can also use environment variables in the configuration file (e.g. `$DOMAIN`, `${DOMAIN}`)
>
> See [examples/docker-compose-postgres-storage/config/config.yaml](.examples/docker-compose-postgres-storage/config/config.yaml) for an example.

If you want to test it locally, see [Docker](#docker).


## Configuration
| Parameter                    | Description                                                                                                                          | Default                    |
|:-----------------------------|:-------------------------------------------------------------------------------------------------------------------------------------|:---------------------------|
| `metrics`                    | Whether to expose metrics at `/metrics`.                                                                                             | `false`                    |
| `storage`                    | [Storage configuration](#storage).                                                                                                   | `{}`                       |
| `alerting`                   | [Alerting configuration](#alerting).                                                                                                 | `{}`                       |
| `endpoints`                  | [Endpoints configuration](#endpoints).                                                                                               | Required `[]`              |
| `external-endpoints`         | [External Endpoints configuration](#external-endpoints).                                                                             | `[]`                       |
| `security`                   | [Security configuration](#security).                                                                                                 | `{}`                       |
| `disable-monitoring-lock`    | Whether to [disable the monitoring lock](#disable-monitoring-lock).                                                                  | `false`                    |
| `skip-invalid-config-update` | Whether to ignore invalid configuration update. <br />See [Reloading configuration on the fly](#reloading-configuration-on-the-fly). | `false`                    |
| `web`                        | Web configuration.                                                                                                                   | `{}`                       |
| `web.address`                | Address to listen on.                                                                                                                | `0.0.0.0`                  |
| `web.port`                   | Port to listen on.                                                                                                                   | `8080`                     |
| `web.read-buffer-size`       | Buffer size for reading requests from a connection. Also limit for the maximum header size.                                          | `8192`                     |
| `web.tls.certificate-file`   | Optional public certificate file for TLS in PEM format.                                                                              | ``                         |
| `web.tls.private-key-file`   | Optional private key file for TLS in PEM format.                                                                                     | ``                         |
| `ui`                         | UI configuration.                                                                                                                    | `{}`                       |
| `ui.title`                   | [Title of the document](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/title).                                            | `Health Dashboard ǀ Gatus` |
| `ui.description`             | Meta description for the page.                                                                                                       | `Gatus is an advanced...`. |
| `ui.header`                  | Header at the top of the dashboard.                                                                                                  | `Health Status`            |
| `ui.logo`                    | URL to the logo to display.                                                                                                          | `""`                       |
| `ui.link`                    | Link to open when the logo is clicked.                                                                                               | `""`                       |
| `ui.buttons`                 | List of buttons to display below the header.                                                                                         | `[]`                       |
| `ui.buttons[].name`          | Text to display on the button.                                                                                                       | Required `""`              |
| `ui.buttons[].link`          | Link to open when the button is clicked.                                                                                             | Required `""`              |
| `ui.custom-css`              | Custom CSS                                                                                                                           | `""`                       |
| `ui.dark-mode`               | Whether to enable dark mode by default. Note that this is superseded by the user's operating system theme preferences.               | `true`                     |
| `maintenance`                | [Maintenance configuration](#maintenance).                                                                                           | `{}`                       |

If you want more verbose logging, you may set the `GATUS_LOG_LEVEL` environment variable to `DEBUG`.
Conversely, if you want less verbose logging, you can set the aforementioned environment variable to `WARN`, `ERROR` or `FATAL`.
The default value for `GATUS_LOG_LEVEL` is `INFO`.

### Endpoints
Endpoints are URLs, applications, or services that you want to monitor. Each endpoint has a list of conditions that are
evaluated on an interval that you define. If any condition fails, the endpoint is considered as unhealthy.
You can then configure alerts to be triggered when an endpoint is unhealthy once a certain threshold is reached.

| Parameter                                       | Description                                                                                                                                 | Default                    |
|:------------------------------------------------|:--------------------------------------------------------------------------------------------------------------------------------------------|:---------------------------|
| `endpoints`                                     | List of endpoints to monitor.                                                                                                               | Required `[]`              |
| `endpoints[].enabled`                           | Whether to monitor the endpoint.                                                                                                            | `true`                     |
| `endpoints[].name`                              | Name of the endpoint. Can be anything.                                                                                                      | Required `""`              |
| `endpoints[].group`                             | Group name. Used to group multiple endpoints together on the dashboard. <br />See [Endpoint groups](#endpoint-groups).                      | `""`                       |
| `endpoints[].url`                               | URL to send the request to.                                                                                                                 | Required `""`              |
| `endpoints[].method`                            | Request method.                                                                                                                             | `GET`                      |
| `endpoints[].conditions`                        | Conditions used to determine the health of the endpoint. <br />See [Conditions](#conditions).                                               | `[]`                       |
| `endpoints[].interval`                          | Duration to wait between every status check.                                                                                                | `60s`                      |
| `endpoints[].graphql`                           | Whether to wrap the body in a query param (`{"query":"$body"}`).                                                                            | `false`                    |
| `endpoints[].body`                              | Request body.                                                                                                                               | `""`                       |
| `endpoints[].headers`                           | Request headers.                                                                                                                            | `{}`                       |
| `endpoints[].dns`                               | Configuration for an endpoint of type DNS. <br />See [Monitoring an endpoint using DNS queries](#monitoring-an-endpoint-using-dns-queries). | `""`                       |
| `endpoints[].dns.query-type`                    | Query type (e.g. MX).                                                                                                                       | `""`                       |
| `endpoints[].dns.query-name`                    | Query name (e.g. example.com).                                                                                                              | `""`                       |
| `endpoints[].ssh`                               | Configuration for an endpoint of type SSH. <br />See [Monitoring an endpoint using SSH](#monitoring-an-endpoint-using-ssh).                 | `""`                       |
| `endpoints[].ssh.username`                      | SSH username (e.g. example).                                                                                                                | Required `""`              |
| `endpoints[].ssh.password`                      | SSH password (e.g. password).                                                                                                               | Required `""`              |
| `endpoints[].alerts`                            | List of all alerts for a given endpoint. <br />See [Alerting](#alerting).                                                                   | `[]`                       |
| `endpoints[].maintenance-windows`               | List of all maintenance windows for a given endpoint. <br />See [Maintenance](#maintenance).                                                | `[]`                       |
| `endpoints[].client`                            | [Client configuration](#client-configuration).                                                                                              | `{}`                       |
| `endpoints[].ui`                                | UI configuration at the endpoint level.                                                                                                     | `{}`                       |
| `endpoints[].ui.hide-conditions`                | Whether to hide conditions from the results. Note that this only hides conditions from results evaluated from the moment this was enabled.  | `false`                    |
| `endpoints[].ui.hide-hostname`                  | Whether to hide the hostname from the results.                                                                                              | `false`                    |
| `endpoints[].ui.hide-port`                      | Whether to hide the port from the results.                                                                                                  | `false`                    |
| `endpoints[].ui.hide-url`                       | Whether to hide the URL from the results. Useful if the URL contains a token.                                                               | `false`                    |
| `endpoints[].ui.dont-resolve-failed-conditions` | Whether to resolve failed conditions for the UI.                                                                                            | `false`                    |
| `endpoints[].ui.badge.response-time`            | List of response time thresholds. Each time a threshold is reached, the badge has a different color.                                        | `[50, 200, 300, 500, 750]` |

You may use the following placeholders in the body (`endpoints[].body`):
- `[ENDPOINT_NAME]` (resolved from `endpoints[].name`)
- `[ENDPOINT_GROUP]` (resolved from `endpoints[].group`)
- `[ENDPOINT_URL]` (resolved from `endpoints[].url`)
- `[LOCAL_ADDRESS]` (resolves to the local IP and port like `192.0.2.1:25` or `[2001:db8::1]:80`)
- `[RANDOM_STRING_N]` (resolves to a random string of numbers and letters of length N (max: 8192))


### External Endpoints
Unlike regular endpoints, external endpoints are not monitored by Gatus, but they are instead pushed programmatically.
This allows you to monitor anything you want, even when what you want to check lives in an environment that would not normally be accessible by Gatus.

For instance:
- You can create your own agent that lives in a private network and pushes the status of your services to a publicly-exposed Gatus instance
- You can monitor services that are not supported by Gatus
- You can implement your own monitoring system while using Gatus as the dashboard

| Parameter                                 | Description                                                                                                                       | Default        |
|:------------------------------------------|:----------------------------------------------------------------------------------------------------------------------------------|:---------------|
| `external-endpoints`                      | List of endpoints to monitor.                                                                                                     | `[]`           |
| `external-endpoints[].enabled`            | Whether to monitor the endpoint.                                                                                                  | `true`         |
| `external-endpoints[].name`               | Name of the endpoint. Can be anything.                                                                                            | Required `""`  |
| `external-endpoints[].group`              | Group name. Used to group multiple endpoints together on the dashboard. <br />See [Endpoint groups](#endpoint-groups).            | `""`           |
| `external-endpoints[].token`              | Bearer token required to push status to.                                                                                          | Required `""`  |
| `external-endpoints[].alerts`             | List of all alerts for a given endpoint. <br />See [Alerting](#alerting).                                                         | `[]`           |
| `external-endpoints[].heartbeat`          | Heartbeat configuration for monitoring when the external endpoint stops sending updates.                                          | `{}`           |
| `external-endpoints[].heartbeat.interval` | Expected interval between updates. If no update is received within this interval, alerts will be triggered. Must be at least 10s. | `0` (disabled) |

Example:
```yaml
external-endpoints:
  - name: ext-ep-test
    group: core
    token: "potato"
    heartbeat:
      interval: 30m  # Automatically create a failure if no update is received within 30 minutes
    alerts:
      - type: discord
        description: "healthcheck failed"
        send-on-resolved: true
```

To push the status of an external endpoint, the request would have to look like this:
```
POST /api/v1/endpoints/{key}/external?success={success}&error={error}&duration={duration}
```
Where:
- `{key}` has the pattern `<GROUP_NAME>_<ENDPOINT_NAME>` in which both variables have ` `, `/`, `_`, `,`, `.` and `#` replaced by `-`.
  - Using the example configuration above, the key would be `core_ext-ep-test`.
- `{success}` is a boolean (`true` or `false`) value indicating whether the health check was successful or not.
- `{error}` (optional): a string describing the reason for a failed health check. If {success} is false, this should contain the error message; if the check is successful.
- `{duration}` (optional): the time that the request took as a duration string (e.g. 10s). 

You must also pass the token as a `Bearer` token in the `Authorization` header.


### Conditions
Here are some examples of conditions you can use:

| Condition                        | Description                                         | Passing values             | Failing values   |
|:---------------------------------|:----------------------------------------------------|:---------------------------|------------------|
| `[STATUS] == 200`                | Status must be equal to 200                         | 200                        | 201, 404, ...    |
| `[STATUS] < 300`                 | Status must lower than 300                          | 200, 201, 299              | 301, 302, ...    |
| `[STATUS] <= 299`                | Status must be less than or equal to 299            | 200, 201, 299              | 301, 302, ...    |
| `[STATUS] > 400`                 | Status must be greater than 400                     | 401, 402, 403, 404         | 400, 200, ...    |
| `[STATUS] == any(200, 429)`      | Status must be either 200 or 429                    | 200, 429                   | 201, 400, ...    |
| `[CONNECTED] == true`            | Connection to host must've been successful          | true                       | false            |
| `[RESPONSE_TIME] < 500`          | Response time must be below 500ms                   | 100ms, 200ms, 300ms        | 500ms, 501ms     |
| `[IP] == 127.0.0.1`              | Target IP must be 127.0.0.1                         | 127.0.0.1                  | 0.0.0.0          |
| `[BODY] == 1`                    | The body must be equal to 1                         | 1                          | `{}`, `2`, ...   |
| `[BODY].user.name == john`       | JSONPath value of `$.user.name` is equal to `john`  | `{"user":{"name":"john"}}` |                  |
| `[BODY].data[0].id == 1`         | JSONPath value of `$.data[0].id` is equal to 1      | `{"data":[{"id":1}]}`      |                  |
| `[BODY].age == [BODY].id`        | JSONPath value of `$.age` is equal JSONPath `$.id`  | `{"age":1,"id":1}`         |                  |
| `len([BODY].data) < 5`           | Array at JSONPath `$.data` has less than 5 elements | `{"data":[{"id":1}]}`      |                  |
| `len([BODY].name) == 8`          | String at JSONPath `$.name` has a length of 8       | `{"name":"john.doe"}`      | `{"name":"bob"}` |
| `has([BODY].errors) == false`    | JSONPath `$.errors` does not exist                  | `{"name":"john.doe"}`      | `{"errors":[]}`  |
| `has([BODY].users) == true`      | JSONPath `$.users` exists                           | `{"users":[]}`             | `{}`             |
| `[BODY].name == pat(john*)`      | String at JSONPath `$.name` matches pattern `john*` | `{"name":"john.doe"}`      | `{"name":"bob"}` |
| `[BODY].id == any(1, 2)`         | Value at JSONPath `$.id` is equal to `1` or `2`     | 1, 2                       | 3, 4, 5          |
| `[CERTIFICATE_EXPIRATION] > 48h` | Certificate expiration is more than 48h away        | 49h, 50h, 123h             | 1h, 24h, ...     |
| `[DOMAIN_EXPIRATION] > 720h`     | The domain must expire in more than 720h            | 4000h                      | 1h, 24h, ...     |


#### Placeholders
| Placeholder                | Description                                                                               | Example of resolved value                    |
|:---------------------------|:------------------------------------------------------------------------------------------|:---------------------------------------------|
| `[STATUS]`                 | Resolves into the HTTP status of the request                                              | `404`                                        |
| `[RESPONSE_TIME]`          | Resolves into the response time the request took, in ms                                   | `10`                                         |
| `[IP]`                     | Resolves into the IP of the target host                                                   | `192.168.0.232`                              |
| `[BODY]`                   | Resolves into the response body. Supports JSONPath.                                       | `{"name":"john.doe"}`                        |
| `[CONNECTED]`              | Resolves into whether a connection could be established                                   | `true`                                       |
| `[CERTIFICATE_EXPIRATION]` | Resolves into the duration before certificate expiration (valid units are "s", "m", "h".) | `24h`, `48h`, 0 (if not protocol with certs) |
| `[DOMAIN_EXPIRATION]`      | Resolves into the duration before the domain expires (valid units are "s", "m", "h".)     | `24h`, `48h`, `1234h56m78s`                  |
| `[DNS_RCODE]`              | Resolves into the DNS status of the response                                              | `NOERROR`                                    |


#### Functions
| Function | Description                                                                                                                                                                                                                         | Example                            |
|:---------|:------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|:-----------------------------------|
| `len`    | If the given path leads to an array, returns its length. Otherwise, the JSON at the given path is minified and converted to a string, and the resulting number of characters is returned. Works only with the `[BODY]` placeholder. | `len([BODY].username) > 8`         |
| `has`    | Returns `true` or `false` based on whether a given path is valid. Works only with the `[BODY]` placeholder.                                                                                                                         | `has([BODY].errors) == false`      |
| `pat`    | Specifies that the string passed as parameter should be evaluated as a pattern. Works only with `==` and `!=`.                                                                                                                      | `[IP] == pat(192.168.*)`           |
| `any`    | Specifies that any one of the values passed as parameters is a valid value. Works only with `==` and `!=`.                                                                                                                          | `[BODY].ip == any(127.0.0.1, ::1)` |

> 💡 Use `pat` only when you need to. `[STATUS] == pat(2*)` is a lot more expensive than `[STATUS] < 300`.


### Storage
| Parameter                           | Description                                                                                                                                        | Default    |
|:------------------------------------|:---------------------------------------------------------------------------------------------------------------------------------------------------|:-----------|
| `storage`                           | Storage configuration                                                                                                                              | `{}`       |
| `storage.path`                      | Path to persist the data in. Only supported for types `sqlite` and `postgres`.                                                                     | `""`       |
| `storage.type`                      | Type of storage. Valid types: `memory`, `sqlite`, `postgres`.                                                                                      | `"memory"` |
| `storage.caching`                   | Whether to use write-through caching. Improves loading time for large dashboards. <br />Only supported if `storage.type` is `sqlite` or `postgres` | `false`    |
| `storage.maximum-number-of-results` | The maximum number of results that an endpoint can have                                                                                            | `100`      |
| `storage.maximum-number-of-events`  | The maximum number of events that an endpoint can have                                                                                             | `50`       |

The results for each endpoint health check as well as the data for uptime and the past events must be persisted
so that they can be displayed on the dashboard. These parameters allow you to configure the storage in question.

- If `storage.type` is `memory` (default):
```yaml
# Note that this is the default value, and you can omit the storage configuration altogether to achieve the same result.
# Because the data is stored in memory, the data will not survive a restart.
storage:
  type: memory
  maximum-number-of-results: 200
  maximum-number-of-events: 5
```
- If `storage.type` is `sqlite`, `storage.path` must not be blank:
```yaml
storage:
  type: sqlite
  path: data.db
```
See [examples/docker-compose-sqlite-storage](.examples/docker-compose-sqlite-storage) for an example.

- If `storage.type` is `postgres`, `storage.path` must be the connection URL:
```yaml
storage:
  type: postgres
  path: "postgres://user:password@127.0.0.1:5432/gatus?sslmode=disable"
```
See [examples/docker-compose-postgres-storage](.examples/docker-compose-postgres-storage) for an example.


### Client configuration
In order to support a wide range of environments, each monitored endpoint has a unique configuration for
the client used to send the request.

| Parameter                              | Description                                                                 | Default         |
|:---------------------------------------|:----------------------------------------------------------------------------|:----------------|
| `client.insecure`                      | Whether to skip verifying the server's certificate chain and host name.     | `false`         |
| `client.ignore-redirect`               | Whether to ignore redirects (true) or follow them (false, default).         | `false`         |
| `client.timeout`                       | Duration before timing out.                                                 | `10s`           |
| `client.dns-resolver`                  | Override the DNS resolver using the format `{proto}://{host}:{port}`.       | `""`            |
| `client.oauth2`                        | OAuth2 client configuration.                                                | `{}`            |
| `client.oauth2.token-url`              | The token endpoint URL                                                      | required `""`   |
| `client.oauth2.client-id`              | The client id which should be used for the `Client credentials flow`        | required `""`   |
| `client.oauth2.client-secret`          | The client secret which should be used for the `Client credentials flow`    | required `""`   |
| `client.oauth2.scopes[]`               | A list of `scopes` which should be used for the `Client credentials flow`.  | required `[""]` |
| `client.proxy-url`                     | The URL of the proxy to use for the client                                  | `""`            |
| `client.identity-aware-proxy`          | Google Identity-Aware-Proxy client configuration.                           | `{}`            |
| `client.identity-aware-proxy.audience` | The Identity-Aware-Proxy audience. (client-id of the IAP oauth2 credential) | required `""`   |
| `client.tls.certificate-file`          | Path to a client certificate (in PEM format) for mTLS configurations.       | `""`            |
| `client.tls.private-key-file`          | Path to a client private key (in PEM format) for mTLS configurations.       | `""`            |
| `client.tls.renegotiation`             | Type of renegotiation support to provide. (`never`, `freely`, `once`).      | `"never"`       |
| `client.network`                       | The network to use for ICMP endpoint client (`ip`, `ip4` or `ip6`).         | `"ip"`          |


> 📝 Some of these parameters are ignored based on the type of endpoint. For instance, there's no certificate involved
> in ICMP requests (ping), therefore, setting `client.insecure` to `true` for an endpoint of that type will not do anything.

This default configuration is as follows:

```yaml
client:
  insecure: false
  ignore-redirect: false
  timeout: 10s
```

Note that this configuration is only available under `endpoints[]`, `alerting.mattermost` and `alerting.custom`.

Here's an example with the client configuration under `endpoints[]`:

```yaml
endpoints:
  - name: website
    url: "https://twin.sh/health"
    client:
      insecure: false
      ignore-redirect: false
      timeout: 10s
    conditions:
      - "[STATUS] == 200"
```

This example shows how you can specify a custom DNS resolver:

```yaml
endpoints:
  - name: with-custom-dns-resolver
    url: "https://your.health.api/health"
    client:
      dns-resolver: "tcp://8.8.8.8:53"
    conditions:
      - "[STATUS] == 200"
```

This example shows how you can use the `client.oauth2` configuration to query a backend API with `Bearer token`:

```yaml
endpoints:
  - name: with-custom-oauth2
    url: "https://your.health.api/health"
    client:
      oauth2:
        token-url: https://your-token-server/token
        client-id: 00000000-0000-0000-0000-000000000000
        client-secret: your-client-secret
        scopes: ['https://your.health.api/.default']
    conditions:
      - "[STATUS] == 200"
```

This example shows how you can use the `client.identity-aware-proxy` configuration to query a backend API with `Bearer token` using Google Identity-Aware-Proxy:

```yaml
endpoints:
  - name: with-custom-iap
    url: "https://my.iap.protected.app/health"
    client:
      identity-aware-proxy:
        audience: "XXXXXXXX-XXXXXXXXXXXX.apps.googleusercontent.com"
    conditions:
      - "[STATUS] == 200"
```

> 📝 Note that Gatus will use the [gcloud default credentials](https://cloud.google.com/docs/authentication/application-default-credentials) within its environment to generate the token.

This example shows you how you can use the `client.tls` configuration to perform an mTLS query to a backend API:

```yaml
endpoints:
  - name: website
    url: "https://your.mtls.protected.app/health"
    client:
      tls:
        certificate-file: /path/to/user_cert.pem
        private-key-file: /path/to/user_key.pem
        renegotiation: once
    conditions:
      - "[STATUS] == 200"
```

> 📝 Note that if running in a container, you must volume mount the certificate and key into the container.

### Alerting
Gatus supports multiple alerting providers, such as Slack and PagerDuty, and supports different alerts for each
individual endpoints with configurable descriptions and thresholds.

Alerts are configured at the endpoint level like so:

| Parameter                            | Description                                                                    | Default       |
|:-------------------------------------|:-------------------------------------------------------------------------------|:--------------|
| `alerts`                             | List of all alerts for a given endpoint.                                       | `[]`          |
| `alerts[].type`                      | Type of alert. <br />See table below for all valid types.                      | Required `""` |
| `alerts[].enabled`                   | Whether to enable the alert.                                                   | `true`        |
| `alerts[].failure-threshold`         | Number of failures in a row needed before triggering the alert.                | `3`           |
| `alerts[].success-threshold`         | Number of successes in a row before an ongoing incident is marked as resolved. | `2`           |
| `alerts[].minimum-reminder-interval` | Configuration for setting an interval between reminders. (e.g. 30m, 24h)       | `""`          |
| `alerts[].send-on-resolved`          | Whether to send a notification once a triggered alert is marked as resolved.   | `false`       |
| `alerts[].description`               | Description of the alert. Will be included in the alert sent.                  | `""`          |
| `alerts[].provider-override`         | Alerting provider configuration override for the given alert type              | `{}`          |

Here's an example of what an alert configuration might look like at the endpoint level:
```yaml
endpoints:
  - name: example
    url: "https://example.org"
    conditions:
      - "[STATUS] == 200"
    alerts:
      - type: slack
        description: "healthcheck failed"
        send-on-resolved: true
```

You can also override global provider configuration by using `alerts[].provider-override`, like so:
```yaml
endpoints:
  - name: example
    url: "https://example.org"
    conditions:
      - "[STATUS] == 200"
    alerts:
      - type: slack
        provider-override:
          webhook-url: "https://hooks.slack.com/services/**********/**********/**********"
```

> 📝 If an alerting provider is not properly configured, all alerts configured with the provider's type will be
> ignored.

| Parameter                  | Description                                                                                                                             | Default |
|:---------------------------|:----------------------------------------------------------------------------------------------------------------------------------------|:--------|
| `alerting.awsses`          | Configuration for alerts of type `awsses`. <br />See [Configuring AWS SES alerts](#configuring-aws-ses-alerts).                         | `{}`    |
| `alerting.custom`          | Configuration for custom actions on failure or alerts. <br />See [Configuring Custom alerts](#configuring-custom-alerts).               | `{}`    |
| `alerting.discord`         | Configuration for alerts of type `discord`. <br />See [Configuring Discord alerts](#configuring-discord-alerts).                        | `{}`    |
| `alerting.email`           | Configuration for alerts of type `email`. <br />See [Configuring Email alerts](#configuring-email-alerts).                              | `{}`    |
| `alerting.gitea`           | Configuration for alerts of type `gitea`. <br />See [Configuring Gitea alerts](#configuring-gitea-alerts).                              | `{}`    |
| `alerting.github`          | Configuration for alerts of type `github`. <br />See [Configuring GitHub alerts](#configuring-github-alerts).                           | `{}`    |
| `alerting.gitlab`          | Configuration for alerts of type `gitlab`. <br />See [Configuring GitLab alerts](#configuring-gitlab-alerts).                           | `{}`    |
| `alerting.googlechat`      | Configuration for alerts of type `googlechat`. <br />See [Configuring Google Chat alerts](#configuring-google-chat-alerts).             | `{}`    |
| `alerting.gotify`          | Configuration for alerts of type `gotify`. <br />See [Configuring Gotify alerts](#configuring-gotify-alerts).                           | `{}`    |
| `alerting.ilert`           | Configuration for alerts of type `ilert`. <br />See [Configuring ilert alerts](#configuring-ilert-alerts).                              | `{}`    |
| `alerting.incident-io`     | Configuration for alerts of type `incident-io`. <br />See [Configuring Incident.io alerts](#configuring-incidentio-alerts).             | `{}`    |
| `alerting.jetbrainsspace`  | Configuration for alerts of type `jetbrainsspace`. <br />See [Configuring JetBrains Space alerts](#configuring-jetbrains-space-alerts). | `{}`    |
| `alerting.matrix`          | Configuration for alerts of type `matrix`. <br />See [Configuring Matrix alerts](#configuring-matrix-alerts).                           | `{}`    |
| `alerting.mattermost`      | Configuration for alerts of type `mattermost`. <br />See [Configuring Mattermost alerts](#configuring-mattermost-alerts).               | `{}`    |
| `alerting.messagebird`     | Configuration for alerts of type `messagebird`. <br />See [Configuring Messagebird alerts](#configuring-messagebird-alerts).            | `{}`    |
| `alerting.ntfy`            | Configuration for alerts of type `ntfy`. <br />See [Configuring Ntfy alerts](#configuring-ntfy-alerts).                                 | `{}`    |
| `alerting.opsgenie`        | Configuration for alerts of type `opsgenie`. <br />See [Configuring Opsgenie alerts](#configuring-opsgenie-alerts).                     | `{}`    |
| `alerting.pagerduty`       | Configuration for alerts of type `pagerduty`. <br />See [Configuring PagerDuty alerts](#configuring-pagerduty-alerts).                  | `{}`    |
| `alerting.pushover`        | Configuration for alerts of type `pushover`. <br />See [Configuring Pushover alerts](#configuring-pushover-alerts).                     | `{}`    |
| `alerting.slack`           | Configuration for alerts of type `slack`. <br />See [Configuring Slack alerts](#configuring-slack-alerts).                              | `{}`    |
| `alerting.teams`           | Configuration for alerts of type `teams`. *(Deprecated)* <br />See [Configuring Teams alerts](#configuring-teams-alerts-deprecated).    | `{}`    |
| `alerting.teams-workflows` | Configuration for alerts of type `teams-workflows`. <br />See [Configuring Teams Workflow alerts](#configuring-teams-workflow-alerts).  | `{}`    |
| `alerting.telegram`        | Configuration for alerts of type `telegram`. <br />See [Configuring Telegram alerts](#configuring-telegram-alerts).                     | `{}`    |
| `alerting.twilio`          | Settings for alerts of type `twilio`. <br />See [Configuring Twilio alerts](#configuring-twilio-alerts).                                | `{}`    |
| `alerting.zulip`           | Configuration for alerts of type `zulip`. <br />See [Configuring Zulip alerts](#configuring-zulip-alerts).                              | `{}`    |
| `alerting.homeassistant`   | Configuration for alerts of type `homeassistant`. <br />See [Configuring HomeAssistant alerts](#configuring-homeassistant-alerts).        | `{}`    |


#### Configuring AWS SES alerts
| Parameter                            | Description                                                                                | Default       |
|:-------------------------------------|:-------------------------------------------------------------------------------------------|:--------------|
| `alerting.aws-ses`                   | Settings for alerts of type `aws-ses`                                                      | `{}`          |
| `alerting.aws-ses.access-key-id`     | AWS Access Key ID                                                                          | Optional `""` |
| `alerting.aws-ses.secret-access-key` | AWS Secret Access Key                                                                      | Optional `""` |
| `alerting.aws-ses.region`            | AWS Region                                                                                 | Required `""` |
| `alerting.aws-ses.from`              | The Email address to send the emails from (should be registered in SES)                    | Required `""` |
| `alerting.aws-ses.to`                | Comma separated list of email address to notify                                            | Required `""` |
| `alerting.aws-ses.default-alert`     | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A           |

```yaml
alerting:
  aws-ses:
    access-key-id: "..."
    secret-access-key: "..."
    region: "us-east-1"
    from: "status@example.com"
    to: "user@example.com"

endpoints:
  - name: website
    interval: 30s
    url: "https://twin.sh/health"
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: aws-ses
        failure-threshold: 5
        send-on-resolved: true
        description: "healthcheck failed"
```

If the `access-key-id` and `secret-access-key` are not defined Gatus will fall back to IAM authentication.

Make sure you have the ability to use `ses:SendEmail`.


#### Configuring Discord alerts
| Parameter                            | Description                                                                                | Default                             |
|:-------------------------------------|:-------------------------------------------------------------------------------------------|:------------------------------------|
| `alerting.discord`                   | Configuration for alerts of type `discord`                                                 | `{}`                                |
| `alerting.discord.webhook-url`       | Discord Webhook URL                                                                        | Required `""`                       |
| `alerting.discord.title`             | Title of the notification                                                                  | `":helmet_with_white_cross: Gatus"` |
| `alerting.discord.default-alert`     | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A                                 |
| `alerting.discord.overrides`         | List of overrides that may be prioritized over the default configuration                   | `[]`                                |
| `alerting.discord.overrides[].group` | Endpoint group for which the configuration will be overridden by this configuration        | `""`                                |
| `alerting.discord.overrides[].*`     | See `alerting.discord.*` parameters                                                        | `{}`                                |

```yaml
alerting:
  discord:
    webhook-url: "https://discord.com/api/webhooks/**********/**********"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: discord
        description: "healthcheck failed"
        send-on-resolved: true
```


#### Configuring Email alerts
| Parameter                          | Description                                                                                   | Default       |
|:-----------------------------------|:----------------------------------------------------------------------------------------------|:--------------|
| `alerting.email`                   | Configuration for alerts of type `email`                                                      | `{}`          |
| `alerting.email.from`              | Email used to send the alert                                                                  | Required `""` |
| `alerting.email.username`          | Username of the SMTP server used to send the alert. If empty, uses `alerting.email.from`.     | `""`          |
| `alerting.email.password`          | Password of the SMTP server used to send the alert. If empty, no authentication is performed. | `""`          |
| `alerting.email.host`              | Host of the mail server (e.g. `smtp.gmail.com`)                                               | Required `""` |
| `alerting.email.port`              | Port the mail server is listening to (e.g. `587`)                                             | Required `0`  |
| `alerting.email.to`                | Email(s) to send the alerts to                                                                | Required `""` |
| `alerting.email.default-alert`     | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert)    | N/A           |
| `alerting.email.client.insecure`   | Whether to skip TLS verification                                                              | `false`       |
| `alerting.email.overrides`         | List of overrides that may be prioritized over the default configuration                      | `[]`          |
| `alerting.email.overrides[].group` | Endpoint group for which the configuration will be overridden by this configuration           | `""`          |
| `alerting.email.overrides[].*`     | See `alerting.email.*` parameters                                                             | `{}`          |

```yaml
alerting:
  email:
    from: "from@example.com"
    username: "from@example.com"
    password: "hunter2"
    host: "mail.example.com"
    port: 587
    to: "recipient1@example.com,recipient2@example.com"
    client:
      insecure: false
    # You can also add group-specific to keys, which will
    # override the to key above for the specified groups
    overrides:
      - group: "core"
        to: "recipient3@example.com,recipient4@example.com"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: email
        description: "healthcheck failed"
        send-on-resolved: true

  - name: back-end
    group: core
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[CERTIFICATE_EXPIRATION] > 48h"
    alerts:
      - type: email
        description: "healthcheck failed"
        send-on-resolved: true
```

> ⚠ Some mail servers are painfully slow.

#### Configuring Gitea alerts

| Parameter                       | Description                                                                                                | Default       |
|:--------------------------------|:-----------------------------------------------------------------------------------------------------------|:--------------|
| `alerting.gitea`                | Configuration for alerts of type `gitea`                                                                   | `{}`          |
| `alerting.gitea.repository-url` | Gitea repository URL (e.g. `https://gitea.com/TwiN/example`)                                               | Required `""` |
| `alerting.gitea.token`          | Personal access token to use for authentication. <br />Must have at least RW on issues and RO on metadata. | Required `""` |
| `alerting.github.default-alert` | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert).                | N/A           |

The Gitea alerting provider creates an issue prefixed with `alert(gatus):` and suffixed with the endpoint's display
name for each alert. If `send-on-resolved` is set to `true` on the endpoint alert, the issue will be automatically
closed when the alert is resolved.

```yaml
alerting:
  gitea:
    repository-url: "https://gitea.com/TwiN/test"
    token: "349d63f16......"

endpoints:
  - name: example
    url: "https://twin.sh/health"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 75"
    alerts:
      - type: gitea
        failure-threshold: 2
        success-threshold: 3
        send-on-resolved: true
        description: "Everything's burning AAAAAHHHHHHHHHHHHHHH"
```

![Gitea alert](.github/assets/gitea-alerts.png)

#### Configuring GitHub alerts

| Parameter                        | Description                                                                                                | Default       |
|:---------------------------------|:-----------------------------------------------------------------------------------------------------------|:--------------|
| `alerting.github`                | Configuration for alerts of type `github`                                                                  | `{}`          |
| `alerting.github.repository-url` | GitHub repository URL (e.g. `https://github.com/TwiN/example`)                                             | Required `""` |
| `alerting.github.token`          | Personal access token to use for authentication. <br />Must have at least RW on issues and RO on metadata. | Required `""` |
| `alerting.github.default-alert`  | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert).                | N/A           |

The GitHub alerting provider creates an issue prefixed with `alert(gatus):` and suffixed with the endpoint's display
name for each alert. If `send-on-resolved` is set to `true` on the endpoint alert, the issue will be automatically
closed when the alert is resolved.

```yaml
alerting:
  github:
    repository-url: "https://github.com/TwiN/test"
    token: "github_pat_12345..."

endpoints:
  - name: example
    url: "https://twin.sh/health"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 75"
    alerts:
      - type: github
        failure-threshold: 2
        success-threshold: 3
        send-on-resolved: true
        description: "Everything's burning AAAAAHHHHHHHHHHHHHHH"
```

![GitHub alert](.github/assets/github-alerts.png)

#### Configuring GitLab alerts
| Parameter                           | Description                                                                                                         | Default       |
|:------------------------------------|:--------------------------------------------------------------------------------------------------------------------|:--------------|
| `alerting.gitlab`                   | Configuration for alerts of type `gitlab`                                                                           | `{}`          |
| `alerting.gitlab.webhook-url`       | GitLab alert webhook URL (e.g. `https://gitlab.com/yourusername/example/alerts/notify/gatus/xxxxxxxxxxxxxxxx.json`) | Required `""` |
| `alerting.gitlab.authorization-key` | GitLab alert authorization key.                                                                                     | Required `""` |
| `alerting.gitlab.severity`          | Override default severity (critical), can be one of `critical, high, medium, low, info, unknown`                    | `""`          |
| `alerting.gitlab.monitoring-tool`   | Override the monitoring tool name (gatus)                                                                           | `"gatus"`     |
| `alerting.gitlab.environment-name`  | Set gitlab environment's name. Required to display alerts on a dashboard.                                           | `""`          |
| `alerting.gitlab.service`           | Override endpoint display name                                                                                      | `""`          |
| `alerting.gitlab.default-alert`     | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert).                         | N/A           |

The GitLab alerting provider creates an alert prefixed with `alert(gatus):` and suffixed with the endpoint's display
name for each alert. If `send-on-resolved` is set to `true` on the endpoint alert, the alert will be automatically
closed when the alert is resolved. See
https://docs.gitlab.com/ee/operations/incident_management/integrations.html#configuration to configure the endpoint.

```yaml
alerting:
  gitlab:
    webhook-url: "https://gitlab.com/hlidotbe/example/alerts/notify/gatus/xxxxxxxxxxxxxxxx.json"
    authorization-key: "12345"

endpoints:
  - name: example
    url: "https://twin.sh/health"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 75"
    alerts:
      - type: gitlab
        failure-threshold: 2
        success-threshold: 3
        send-on-resolved: true
        description: "Everything's burning AAAAAHHHHHHHHHHHHHHH"
```

![GitLab alert](.github/assets/gitlab-alerts.png)


#### Configuring Google Chat alerts
| Parameter                               | Description                                                                                 | Default       |
|:----------------------------------------|:--------------------------------------------------------------------------------------------|:--------------|
| `alerting.googlechat`                   | Configuration for alerts of type `googlechat`                                               | `{}`          |
| `alerting.googlechat.webhook-url`       | Google Chat Webhook URL                                                                     | Required `""` |
| `alerting.googlechat.client`            | Client configuration. <br />See [Client configuration](#client-configuration).              | `{}`          |
| `alerting.googlechat.default-alert`     | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert). | N/A           |
| `alerting.googlechat.overrides`         | List of overrides that may be prioritized over the default configuration                    | `[]`          |
| `alerting.googlechat.overrides[].group` | Endpoint group for which the configuration will be overridden by this configuration         | `""`          |
| `alerting.googlechat.overrides[].*`     | See `alerting.googlechat.*` parameters                                                      | `{}`          |

```yaml
alerting:
  googlechat:
    webhook-url: "https://chat.googleapis.com/v1/spaces/*******/messages?key=**********&token=********"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: googlechat
        description: "healthcheck failed"
        send-on-resolved: true
```


#### Configuring Gotify alerts
| Parameter                                     | Description                                                                                 | Default               |
|:----------------------------------------------|:--------------------------------------------------------------------------------------------|:----------------------|
| `alerting.gotify`                             | Configuration for alerts of type `gotify`                                                   | `{}`                  |
| `alerting.gotify.server-url`                  | Gotify server URL                                                                           | Required `""`         |
| `alerting.gotify.token`                       | Token that is used for authentication.                                                      | Required `""`         |
| `alerting.gotify.priority`                    | Priority of the alert according to Gotify standards.                                        | `5`                   |
| `alerting.gotify.title`                       | Title of the notification                                                                   | `"Gatus: <endpoint>"` |
| `alerting.gotify.default-alert`               | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert). | N/A                   |

#### Configuring ilert alerts
| Parameter                              | Description                                                                                | Default |
|:---------------------------------------|:-------------------------------------------------------------------------------------------|:--------|
| `alerting.ilert`                   | Configuration for alerts of type `ilert`                                               | `{}`    |
| `alerting.ilert.integration-key`   | ilert Alert Source integration key                                                    | `""`    |
| `alerting.ilert.default-alert`     | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A     |
| `alerting.ilert.overrides`         | List of overrides that may be prioritized over the default configuration                   | `[]`    |
| `alerting.ilert.overrides[].group` | Endpoint group for which the configuration will be overridden by this configuration        | `""`    |
| `alerting.ilert.overrides[].*`     | See `alerting.ilert.*` parameters                                                      | `{}`    |

It is highly recommended to set `endpoints[].alerts[].send-on-resolved` to `true` for alerts
of type `ilert`, because unlike other alerts, the operation resulting from setting said
parameter to `true` will not create another alert but mark the alert as resolved on
ilert instead.

Behavior:
- By default, `alerting.ilert.integration-key` is used as the integration key
- If the endpoint being evaluated belongs to a group (`endpoints[].group`) matching the value of `alerting.ilert.overrides[].group`, the provider will use that override's integration key instead of `alerting.ilert.integration-key`'s

```yaml
alerting:
  ilert:
    integration-key: "********************************"
    # You can also add group-specific integration keys, which will
    # override the integration key above for the specified groups
    overrides:
      - group: "core"
        integration-key: "********************************"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: ilert
        failure-threshold: 3
        success-threshold: 5
        send-on-resolved: true
        description: "healthcheck failed"
```

```yaml
alerting:
  gotify:
    server-url: "https://gotify.example"
    token: "**************"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: gotify
        description: "healthcheck failed"
        send-on-resolved: true
```

Here's an example of what the notifications look like:

![Gotify notifications](.github/assets/gotify-alerts.png)


#### Configuring HomeAssistant alerts
To configure HomeAssistant alerts, you'll need to add the following to your configuration file:

```yaml
alerting:
  homeassistant:
    url: "http://homeassistant:8123"  # URL of your HomeAssistant instance
    token: "YOUR_LONG_LIVED_ACCESS_TOKEN"  # Long-lived access token from HomeAssistant

endpoints:
  - name: my-service
    url: "https://my-service.com"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
    alerts:
      - type: homeassistant
        enabled: true
        send-on-resolved: true
        description: "My service health check"
        failure-threshold: 3
        success-threshold: 2
```

The alerts will be sent as events to HomeAssistant with the event type `gatus_alert`. The event data includes:
- `status`: "triggered" or "resolved"
- `endpoint`: The name of the monitored endpoint
- `description`: The alert description if provided
- `conditions`: List of conditions and their results
- `failure_count`: Number of consecutive failures (when triggered)
- `success_count`: Number of consecutive successes (when resolved)

You can use these events in HomeAssistant automations to:
- Send notifications
- Control devices
- Trigger scenes
- Log to history
- And more

Example HomeAssistant automation:
```yaml
automation:
  - alias: "Gatus Alert Handler"
    trigger:
      platform: event
      event_type: gatus_alert
    action:
      - service: notify.notify
        data_template:
          title: "Gatus Alert: {{ trigger.event.data.endpoint }}"
          message: >
            Status: {{ trigger.event.data.status }}
            {% if trigger.event.data.description %}
            Description: {{ trigger.event.data.description }}
            {% endif %}
            {% for condition in trigger.event.data.conditions %}
            {{ '✅' if condition.success else '❌' }} {{ condition.condition }}
            {% endfor %}
```

To get your HomeAssistant long-lived access token:
1. Open HomeAssistant
2. Click on your profile name (bottom left)
3. Scroll down to "Long-Lived Access Tokens"
4. Click "Create Token"
5. Give it a name (e.g., "Gatus")
6. Copy the token - you'll only see it once!


#### Configuring Incident.io alerts
| Parameter                                | Description                                                                                | Default       |
|:-----------------------------------------|:-------------------------------------------------------------------------------------------|:--------------|
| `alerting.incident-io`                   | Configuration for alerts of type `incident-io`                                             | `{}`          |
| `alerting.incident-io.url`               | url to trigger an alert event.                                                             | Required `""` |
| `alerting.incident-io.auth-token`        | Token that is used for authentication.                                                     | Required `""` |
| `alerting.incident-io.source-url`        | Source URL                                                                                 | `""`          |
| `alerting.incident-io.default-alert`     | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A           |
| `alerting.incident-io.overrides`         | List of overrides that may be prioritized over the default configuration                   | `[]`          |
| `alerting.incident-io.overrides[].group` | Endpoint group for which the configuration will be overridden by this configuration        | `""`          |
| `alerting.incident-io.overrides[].*`     | See `alerting.incident-io.*` parameters                                                    | `{}`          |

```yaml
alerting:
  incident-io:
    url: "*****************"
    auth-token: "********************************************"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: incident-io
        description: "healthcheck failed"
        send-on-resolved: true
```
In order to get the required alert source config id and authentication token, you must configure an HTTP alert source.

> **_NOTE:_**  the source config id is of the form `https://api.incident.io/v2/alert_events/http/$ID` and the token is expected to be passed as a bearer token like so: `Authorization: Bearer $TOKEN`


#### Configuring JetBrains Space alerts
| Parameter                                   | Description                                                                                | Default       |
|:--------------------------------------------|:-------------------------------------------------------------------------------------------|:--------------|
| `alerting.jetbrainsspace`                   | Configuration for alerts of type `jetbrainsspace`                                          | `{}`          |
| `alerting.jetbrainsspace.project`           | JetBrains Space project name                                                               | Required `""` |
| `alerting.jetbrainsspace.channel-id`        | JetBrains Space Chat Channel ID                                                            | Required `""` |
| `alerting.jetbrainsspace.token`             | Token that is used for authentication.                                                     | Required `""` |
| `alerting.jetbrainsspace.default-alert`     | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A           |
| `alerting.jetbrainsspace.overrides`         | List of overrides that may be prioritized over the default configuration                   | `[]`          |
| `alerting.jetbrainsspace.overrides[].group` | Endpoint group for which the configuration will be overridden by this configuration        | `""`          |
| `alerting.jetbrainsspace.overrides[].*`     | See `alerting.jetbrainsspace.*` parameters                                                 | `{}`          |

```yaml
alerting:
  jetbrainsspace:
    project: myproject
    channel-id: ABCDE12345
    token: "**************"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
    alerts:
      - type: jetbrainsspace
        description: "healthcheck failed"
        send-on-resolved: true
```

Here's an example of what the notifications look like:

![JetBrains Space notifications](.github/assets/jetbrains-space-alerts.png)


#### Configuring Matrix alerts
| Parameter                                | Description                                                                                | Default                            |
|:-----------------------------------------|:-------------------------------------------------------------------------------------------|:-----------------------------------|
| `alerting.matrix`                        | Configuration for alerts of type `matrix`                                                  | `{}`                               |
| `alerting.matrix.server-url`             | Homeserver URL                                                                             | `https://matrix-client.matrix.org` |
| `alerting.matrix.access-token`           | Bot user access token (see https://webapps.stackexchange.com/q/131056)                     | Required `""`                      |
| `alerting.matrix.internal-room-id`       | Internal room ID of room to send alerts to (can be found in Room Settings > Advanced)      | Required `""`                      |
| `alerting.matrix.default-alert`          | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A                                |

```yaml
alerting:
  matrix:
    server-url: "https://matrix-client.matrix.org"
    access-token: "123456"
    internal-room-id: "!example:matrix.org"

endpoints:
  - name: website
    interval: 5m
    url: "https://twin.sh/health"
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: matrix
        send-on-resolved: true
        description: "healthcheck failed"
```


#### Configuring Mattermost alerts
| Parameter                                     | Description                                                                                 | Default       |
|:----------------------------------------------|:--------------------------------------------------------------------------------------------|:--------------|
| `alerting.mattermost`                         | Configuration for alerts of type `mattermost`                                               | `{}`          |
| `alerting.mattermost.webhook-url`             | Mattermost Webhook URL                                                                      | Required `""` |
| `alerting.mattermost.channel`                 | Mattermost channel name override (optional)                                                 | `""`          |
| `alerting.mattermost.client`                  | Client configuration. <br />See [Client configuration](#client-configuration).              | `{}`          |
| `alerting.mattermost.default-alert`           | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert). | N/A           |
| `alerting.mattermost.overrides`               | List of overrides that may be prioritized over the default configuration                    | `[]`          |
| `alerting.mattermost.overrides[].group`       | Endpoint group for which the configuration will be overridden by this configuration         | `""`          |
| `alerting.mattermost.overrides[].*`           | See `alerting.mattermost.*` parameters                                                      | `{}`          |

```yaml
alerting:
  mattermost:
    webhook-url: "http://**********/hooks/**********"
    client:
      insecure: true

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: mattermost
        description: "healthcheck failed"
        send-on-resolved: true
```

Here's an example of what the notifications look like:

![Mattermost notifications](.github/assets/mattermost-alerts.png)


#### Configuring Messagebird alerts
| Parameter                            | Description                                                                                | Default       |
|:-------------------------------------|:-------------------------------------------------------------------------------------------|:--------------|
| `alerting.messagebird`               | Configuration for alerts of type `messagebird`                                             | `{}`          |
| `alerting.messagebird.access-key`    | Messagebird access key                                                                     | Required `""` |
| `alerting.messagebird.originator`    | The sender of the message                                                                  | Required `""` |
| `alerting.messagebird.recipients`    | The recipients of the message                                                              | Required `""` |
| `alerting.messagebird.default-alert` | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A           |

Example of sending **SMS** text message alert using Messagebird:
```yaml
alerting:
  messagebird:
    access-key: "..."
    originator: "31619191918"
    recipients: "31619191919,31619191920"

endpoints:
  - name: website
    interval: 5m
    url: "https://twin.sh/health"
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: messagebird
        failure-threshold: 3
        send-on-resolved: true
        description: "healthcheck failed"
```


#### Configuring Ntfy alerts
| Parameter                            | Description                                                                                                                                  | Default           |
|:-------------------------------------|:---------------------------------------------------------------------------------------------------------------------------------------------|:------------------|
| `alerting.ntfy`                      | Configuration for alerts of type `ntfy`                                                                                                      | `{}`              |
| `alerting.ntfy.topic`                | Topic at which the alert will be sent                                                                                                        | Required `""`     |
| `alerting.ntfy.url`                  | The URL of the target server                                                                                                                 | `https://ntfy.sh` |
| `alerting.ntfy.token`                | [Access token](https://docs.ntfy.sh/publish/#access-tokens) for restricted topics                                                            | `""`              |
| `alerting.ntfy.email`                | E-mail address for additional e-mail notifications                                                                                           | `""`              |
| `alerting.ntfy.click`                | Website opened when notification is clicked                                                                                                  | `""`              |
| `alerting.ntfy.priority`             | The priority of the alert                                                                                                                    | `3`               |
| `alerting.ntfy.disable-firebase`     | Whether message push delivery via firebase should be disabled. [ntfy.sh defaults to enabled](https://docs.ntfy.sh/publish/#disable-firebase) | `false`           |
| `alerting.ntfy.disable-cache`        | Whether server side message caching should be disabled. [ntfy.sh defaults to enabled](https://docs.ntfy.sh/publish/#message-caching)         | `false`           |
| `alerting.ntfy.default-alert`        | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert)                                                   | N/A               |
| `alerting.ntfy.overrides`            | List of overrides that may be prioritized over the default configuration                                                                     | `[]`              |
| `alerting.ntfy.overrides[].group`    | Endpoint group for which the configuration will be overridden by this configuration                                                          | `""`              |
| `alerting.ntfy.overrides[].*`        | See `alerting.ntfy.*` parameters                                                                                                             | `{}`              |

[ntfy](https://github.com/binwiederhier/ntfy) is an amazing project that allows you to subscribe to desktop
and mobile notifications, making it an awesome addition to Gatus.

Example:
```yaml
alerting:
  ntfy:
    topic: "gatus-test-topic"
    priority: 2
    token: faketoken
    default-alert:
      failure-threshold: 3
      send-on-resolved: true
    # You can also add group-specific to keys, which will
    # override the to key above for the specified groups
    overrides:
      - group: "other"
        topic: "gatus-other-test-topic"
        priority: 4
        click: "https://example.com"

endpoints:
  - name: website
    interval: 5m
    url: "https://twin.sh/health"
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: ntfy
  - name: other example
    group: other
    interval: 30m
    url: "https://example.com"
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
    alerts:
      - type: ntfy
        description: example
```


#### Configuring Opsgenie alerts
| Parameter                         | Description                                                                                | Default              |
|:----------------------------------|:-------------------------------------------------------------------------------------------|:---------------------|
| `alerting.opsgenie`               | Configuration for alerts of type `opsgenie`                                                | `{}`                 |
| `alerting.opsgenie.api-key`       | Opsgenie API Key                                                                           | Required `""`        |
| `alerting.opsgenie.priority`      | Priority level of the alert.                                                               | `P1`                 |
| `alerting.opsgenie.source`        | Source field of the alert.                                                                 | `gatus`              |
| `alerting.opsgenie.entity-prefix` | Entity field prefix.                                                                       | `gatus-`             |
| `alerting.opsgenie.alias-prefix`  | Alias field prefix.                                                                        | `gatus-healthcheck-` |
| `alerting.opsgenie.tags`          | Tags of alert.                                                                             | `[]`                 |
| `alerting.opsgenie.default-alert` | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A                  |

Opsgenie provider will automatically open and close alerts.

```yaml
alerting:
  opsgenie:
    api-key: "00000000-0000-0000-0000-000000000000"
```


#### Configuring PagerDuty alerts
| Parameter                              | Description                                                                                | Default |
|:---------------------------------------|:-------------------------------------------------------------------------------------------|:--------|
| `alerting.pagerduty`                   | Configuration for alerts of type `pagerduty`                                               | `{}`    |
| `alerting.pagerduty.integration-key`   | PagerDuty Events API v2 integration key                                                    | `""`    |
| `alerting.pagerduty.default-alert`     | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A     |
| `alerting.pagerduty.overrides`         | List of overrides that may be prioritized over the default configuration                   | `[]`    |
| `alerting.pagerduty.overrides[].group` | Endpoint group for which the configuration will be overridden by this configuration        | `""`    |
| `alerting.pagerduty.overrides[].*`     | See `alerting.pagerduty.*` parameters                                                      | `{}`    |

It is highly recommended to set `endpoints[].alerts[].send-on-resolved` to `true` for alerts
of type `pagerduty`, because unlike other alerts, the operation resulting from setting said
parameter to `true` will not create another incident but mark the incident as resolved on
PagerDuty instead.

Behavior:
- By default, `alerting.pagerduty.integration-key` is used as the integration key
- If the endpoint being evaluated belongs to a group (`endpoints[].group`) matching the value of `alerting.pagerduty.overrides[].group`, the provider will use that override's integration key instead of `alerting.pagerduty.integration-key`'s

```yaml
alerting:
  pagerduty:
    integration-key: "********************************"
    # You can also add group-specific integration keys, which will
    # override the integration key above for the specified groups
    overrides:
      - group: "core"
        integration-key: "********************************"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: pagerduty
        failure-threshold: 3
        success-threshold: 5
        send-on-resolved: true
        description: "healthcheck failed"

  - name: back-end
    group: core
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[CERTIFICATE_EXPIRATION] > 48h"
    alerts:
      - type: pagerduty
        failure-threshold: 3
        success-threshold: 5
        send-on-resolved: true
        description: "healthcheck failed"
```


#### Configuring Pushover alerts
| Parameter                             | Description                                                                                              | Default                     |
|:--------------------------------------|:---------------------------------------------------------------------------------------------------------|:----------------------------|
| `alerting.pushover`                   | Configuration for alerts of type `pushover`                                                              | `{}`                        |
| `alerting.pushover.application-token` | Pushover application token                                                                               | `""`                        |
| `alerting.pushover.user-key`          | User or group key                                                                                        | `""`                        |
| `alerting.pushover.title`             | Fixed title for all messages sent via Pushover                                                           | `"Gatus: <endpoint>"`       |
| `alerting.pushover.priority`          | Priority of all messages, ranging from -2 (very low) to 2 (emergency)                                    | `0`                         |
| `alerting.pushover.resolved-priority` | Override the priority of messages on resolved, ranging from -2 (very low) to 2 (emergency)               | `0`                         |
| `alerting.pushover.sound`             | Sound of all messages<br />See [sounds](https://pushover.net/api#sounds) for all valid choices.          | `""`                        |
| `alerting.pushover.ttl`               | Set the Time-to-live of the message to be automatically deleted from pushover notifications              | `0`                         |
| `alerting.pushover.device`            | Device to send the message to (optional)<br/>See [devices](https://pushover.net/api#identifiers) for details | `""` (all devices)|
| `alerting.pushover.default-alert`     | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert)               | N/A                         |

```yaml
alerting:
  pushover:
    application-token: "******************************"
    user-key: "******************************"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: pushover
        failure-threshold: 3
        success-threshold: 5
        send-on-resolved: true
        description: "healthcheck failed"
```


#### Configuring Slack alerts
| Parameter                          | Description                                                                                | Default       |
|:-----------------------------------|:-------------------------------------------------------------------------------------------|:--------------|
| `alerting.slack`                   | Configuration for alerts of type `slack`                                                   | `{}`          |
| `alerting.slack.webhook-url`       | Slack Webhook URL                                                                          | Required `""` |
| `alerting.slack.default-alert`     | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A           |
| `alerting.slack.overrides`         | List of overrides that may be prioritized over the default configuration                   | `[]`          |
| `alerting.slack.overrides[].group` | Endpoint group for which the configuration will be overridden by this configuration        | `""`          |
| `alerting.slack.overrides[].*`     | See `alerting.slack.*` parameters                                                          | `{}`          |

```yaml
alerting:
  slack:
    webhook-url: "https://hooks.slack.com/services/**********/**********/**********"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: slack
        description: "healthcheck failed 3 times in a row"
        send-on-resolved: true
      - type: slack
        failure-threshold: 5
        description: "healthcheck failed 5 times in a row"
        send-on-resolved: true
```

Here's an example of what the notifications look like:

![Slack notifications](.github/assets/slack-alerts.png)


#### Configuring Teams alerts *(Deprecated)*

> [!CAUTION]
> **Deprecated:** Office 365 Connectors within Microsoft Teams are being retired ([Source: Microsoft DevBlog](https://devblogs.microsoft.com/microsoft365dev/retirement-of-office-365-connectors-within-microsoft-teams/)).
> Existing connectors will continue to work until December 2025. The new [Teams Workflow Alerts](#configuring-teams-workflow-alerts) should be used with Microsoft Workflows instead of this legacy configuration.

| Parameter                          | Description                                                                                | Default             |
|:-----------------------------------|:-------------------------------------------------------------------------------------------|:--------------------|
| `alerting.teams`                   | Configuration for alerts of type `teams`                                                   | `{}`                |
| `alerting.teams.webhook-url`       | Teams Webhook URL                                                                          | Required `""`       |
| `alerting.teams.default-alert`     | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A                 |
| `alerting.teams.title`             | Title of the notification                                                                  | `"&#x1F6A8; Gatus"` |
| `alerting.teams.client.insecure`   | Whether to skip TLS verification                                                           | `false`             |
| `alerting.teams.overrides`         | List of overrides that may be prioritized over the default configuration                   | `[]`                |
| `alerting.teams.overrides[].group` | Endpoint group for which the configuration will be overridden by this configuration        | `""`                |
| `alerting.teams.overrides[].*`     | See `alerting.teams.*` parameters                                                          | `{}`                |

```yaml
alerting:
  teams:
    webhook-url: "https://********.webhook.office.com/webhookb2/************"
    client:
      insecure: false
    # You can also add group-specific to keys, which will
    # override the to key above for the specified groups
    overrides:
      - group: "core"
        webhook-url: "https://********.webhook.office.com/webhookb3/************"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: teams
        description: "healthcheck failed"
        send-on-resolved: true

  - name: back-end
    group: core
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[CERTIFICATE_EXPIRATION] > 48h"
    alerts:
      - type: teams
        description: "healthcheck failed"
        send-on-resolved: true
```

Here's an example of what the notifications look like:

![Teams notifications](.github/assets/teams-alerts.png)

#### Configuring Teams Workflow alerts

> [!NOTE]
> This alert is compatible with Workflows for Microsoft Teams. To setup the workflow and get the webhook URL, follow the [Microsoft Documentation](https://support.microsoft.com/en-us/office/create-incoming-webhooks-with-workflows-for-microsoft-teams-8ae491c7-0394-4861-ba59-055e33f75498).

| Parameter                                    | Description                                                                                | Default            |
|:---------------------------------------------|:-------------------------------------------------------------------------------------------|:-------------------|
| `alerting.teams-workflows`                   | Configuration for alerts of type `teams`                                                   | `{}`               |
| `alerting.teams-workflows.webhook-url`       | Teams Webhook URL                                                                          | Required `""`      |
| `alerting.teams-workflows.title`             | Title of the notification                                                                  | `"&#x26D1; Gatus"` |
| `alerting.teams-workflows.default-alert`     | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A                |
| `alerting.teams-workflows.overrides`         | List of overrides that may be prioritized over the default configuration                   | `[]`               |
| `alerting.teams-workflows.overrides[].group` | Endpoint group for which the configuration will be overridden by this configuration        | `""`               |
| `alerting.teams-workflows.overrides[].*`     | See `alerting.teams-workflows.*` parameters                                                | `{}`               |

```yaml
alerting:
  teams-workflows:
    webhook-url: "https://********.webhook.office.com/webhookb2/************"
    # You can also add group-specific to keys, which will
    # override the to key above for the specified groups
    overrides:
      - group: "core"
        webhook-url: "https://********.webhook.office.com/webhookb3/************"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: teams-workflows
        description: "healthcheck failed"
        send-on-resolved: true

  - name: back-end
    group: core
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[CERTIFICATE_EXPIRATION] > 48h"
    alerts:
      - type: teams-workflows
        description: "healthcheck failed"
        send-on-resolved: true
```

Here's an example of what the notifications look like:

![Teams Workflow notifications](.github/assets/teams-workflows-alerts.png)


#### Configuring Telegram alerts
| Parameter                             | Description                                                                                | Default                    |
|:--------------------------------------|:-------------------------------------------------------------------------------------------|:---------------------------|
| `alerting.telegram`                   | Configuration for alerts of type `telegram`                                                | `{}`                       |
| `alerting.telegram.token`             | Telegram Bot Token                                                                         | Required `""`              |
| `alerting.telegram.id`                | Telegram User ID                                                                           | Required `""`              |
| `alerting.telegram.topic-id`          | Telegram Topic ID in a group corresponds to `message_thread_id` in the Telegram API        | `""`                       |    
| `alerting.telegram.api-url`           | Telegram API URL                                                                           | `https://api.telegram.org` |
| `alerting.telegram.client`            | Client configuration. <br />See [Client configuration](#client-configuration).             | `{}`                       |
| `alerting.telegram.default-alert`     | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A                        |
| `alerting.telegram.overrides`         | List of overrides that may be prioritized over the default configuration                   | `[]`                       |
| `alerting.telegram.overrides[].group` | Endpoint group for which the configuration will be overridden by this configuration        | `""`                       |
| `alerting.telegram.overrides[].*`     | See `alerting.telegram.*` parameters                                                       | `{}`                       |

```yaml
alerting:
  telegram:
    token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11"
    id: "0123456789"
    topic-id: "7"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
    alerts:
      - type: telegram
        send-on-resolved: true
```

Here's an example of what the notifications look like:

![Telegram notifications](.github/assets/telegram-alerts.png)


#### Configuring Twilio alerts
| Parameter                       | Description                                                                                | Default       |
|:--------------------------------|:-------------------------------------------------------------------------------------------|:--------------|
| `alerting.twilio`               | Settings for alerts of type `twilio`                                                       | `{}`          |
| `alerting.twilio.sid`           | Twilio account SID                                                                         | Required `""` |
| `alerting.twilio.token`         | Twilio auth token                                                                          | Required `""` |
| `alerting.twilio.from`          | Number to send Twilio alerts from                                                          | Required `""` |
| `alerting.twilio.to`            | Number to send twilio alerts to                                                            | Required `""` |
| `alerting.twilio.default-alert` | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A           |

```yaml
alerting:
  twilio:
    sid: "..."
    token: "..."
    from: "+1-234-567-8901"
    to: "+1-234-567-8901"

endpoints:
  - name: website
    interval: 30s
    url: "https://twin.sh/health"
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: twilio
        failure-threshold: 5
        send-on-resolved: true
        description: "healthcheck failed"
```


#### Configuring Zulip alerts
| Parameter                          | Description                                                                         | Default       |
|:-----------------------------------|:------------------------------------------------------------------------------------|:--------------|
| `alerting.zulip`                   | Configuration for alerts of type `discord`                                          | `{}`          |
| `alerting.zulip.bot-email`         | Bot Email                                                                           | Required `""` |
| `alerting.zulip.bot-api-key`       | Bot API key                                                                         | Required `""` |
| `alerting.zulip.domain`            | Full organization domain (e.g.: yourZulipDomain.zulipchat.com)                      | Required `""` |
| `alerting.zulip.channel-id`        | The channel ID where Gatus will send the alerts                                     | Required `""` |
| `alerting.zulip.overrides`         | List of overrides that may be prioritized over the default configuration            | `[]`          |
| `alerting.zulip.overrides[].group` | Endpoint group for which the configuration will be overridden by this configuration | `""`          |
| `alerting.zulip.overrides[].*`     | See `alerting.zulip.*` parameters                                                   | `{}`          |

```yaml
alerting:
  zulip:
    bot-email: gatus-bot@some.zulip.org
    bot-api-key: "********************************"
    domain: some.zulip.org
    channel-id: 123456

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: zulip
        description: "healthcheck failed"
        send-on-resolved: true
```


#### Configuring custom alerts
| Parameter                       | Description                                                                                | Default       |
|:--------------------------------|:-------------------------------------------------------------------------------------------|:--------------|
| `alerting.custom`               | Configuration for custom actions on failure or alerts                                      | `{}`          |
| `alerting.custom.url`           | Custom alerting request url                                                                | Required `""` |
| `alerting.custom.method`        | Request method                                                                             | `GET`         |
| `alerting.custom.body`          | Custom alerting request body.                                                              | `""`          |
| `alerting.custom.headers`       | Custom alerting request headers                                                            | `{}`          |
| `alerting.custom.client`        | Client configuration. <br />See [Client configuration](#client-configuration).             | `{}`          |
| `alerting.custom.default-alert` | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A           |

While they're called alerts, you can use this feature to call anything.

For instance, you could automate rollbacks by having an application that keeps tracks of new deployments, and by
leveraging Gatus, you could have Gatus call that application endpoint when an endpoint starts failing. Your application
would then check if the endpoint that started failing was part of the recently deployed application, and if it was,
then automatically roll it back.

Furthermore, you may use the following placeholders in the body (`alerting.custom.body`) and in the url (`alerting.custom.url`):
- `[ALERT_DESCRIPTION]` (resolved from `endpoints[].alerts[].description`)
- `[ENDPOINT_NAME]` (resolved from `endpoints[].name`)
- `[ENDPOINT_GROUP]` (resolved from `endpoints[].group`)
- `[ENDPOINT_URL]` (resolved from `endpoints[].url`)
- `[RESULT_ERRORS]` (resolved from the health evaluation of a given health check)

If you have an alert using the `custom` provider with `send-on-resolved` set to `true`, you can use the
`[ALERT_TRIGGERED_OR_RESOLVED]` placeholder to differentiate the notifications.
The aforementioned placeholder will be replaced by `TRIGGERED` or `RESOLVED` accordingly, though it can be modified
(details at the end of this section).

For all intents and purposes, we'll configure the custom alert with a Slack webhook, but you can call anything you want.
```yaml
alerting:
  custom:
    url: "https://hooks.slack.com/services/**********/**********/**********"
    method: "POST"
    body: |
      {
        "text": "[ALERT_TRIGGERED_OR_RESOLVED]: [ENDPOINT_GROUP] - [ENDPOINT_NAME] - [ALERT_DESCRIPTION] - [RESULT_ERRORS]"
      }
endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: custom
        failure-threshold: 10
        success-threshold: 3
        send-on-resolved: true
        description: "health check failed"
```

Note that you can customize the resolved values for the `[ALERT_TRIGGERED_OR_RESOLVED]` placeholder like so:
```yaml
alerting:
  custom:
    placeholders:
      ALERT_TRIGGERED_OR_RESOLVED:
        TRIGGERED: "partial_outage"
        RESOLVED: "operational"
```
As a result, the `[ALERT_TRIGGERED_OR_RESOLVED]` in the body of first example of this section would be replaced by
`partial_outage` when an alert is triggered and `operational` when an alert is resolved.


#### Setting a default alert
| Parameter                                    | Description                                                                   | Default |
|:---------------------------------------------|:------------------------------------------------------------------------------|:--------|
| `alerting.*.default-alert.enabled`           | Whether to enable the alert                                                   | N/A     |
| `alerting.*.default-alert.failure-threshold` | Number of failures in a row needed before triggering the alert                | N/A     |
| `alerting.*.default-alert.success-threshold` | Number of successes in a row before an ongoing incident is marked as resolved | N/A     |
| `alerting.*.default-alert.send-on-resolved`  | Whether to send a notification once a triggered alert is marked as resolved   | N/A     |
| `alerting.*.default-alert.description`       | Description of the alert. Will be included in the alert sent                  | N/A     |

> ⚠ You must still specify the `type` of the alert in the endpoint configuration even if you set the default alert of a provider.

While you can specify the alert configuration directly in the endpoint definition, it's tedious and may lead to a very
long configuration file.

To avoid such problem, you can use the `default-alert` parameter present in each provider configuration:
```yaml
alerting:
  slack:
    webhook-url: "https://hooks.slack.com/services/**********/**********/**********"
    default-alert:
      description: "health check failed"
      send-on-resolved: true
      failure-threshold: 5
      success-threshold: 5
```

As a result, your Gatus configuration looks a lot tidier:
```yaml
endpoints:
  - name: example
    url: "https://example.org"
    conditions:
      - "[STATUS] == 200"
    alerts:
      - type: slack

  - name: other-example
    url: "https://example.com"
    conditions:
      - "[STATUS] == 200"
    alerts:
      - type: slack
```

It also allows you to do things like this:
```yaml
endpoints:
  - name: example
    url: "https://example.org"
    conditions:
      - "[STATUS] == 200"
    alerts:
      - type: slack
        failure-threshold: 5
      - type: slack
        failure-threshold: 10
      - type: slack
        failure-threshold: 15
```

Of course, you can also mix alert types:
```yaml
alerting:
  slack:
    webhook-url: "https://hooks.slack.com/services/**********/**********/**********"
    default-alert:
      failure-threshold: 3
  pagerduty:
    integration-key: "********************************"
    default-alert:
      failure-threshold: 5

endpoints:
  - name: endpoint-1
    url: "https://example.org"
    conditions:
      - "[STATUS] == 200"
    alerts:
      - type: slack
      - type: pagerduty

  - name: endpoint-2
    url: "https://example.org"
    conditions:
      - "[STATUS] == 200"
    alerts:
      - type: slack
      - type: pagerduty
```


### Maintenance
If you have maintenance windows, you may not want to be annoyed by alerts.
To do that, you'll have to use the maintenance configuration:

| Parameter              | Description                                                                                                                                                                                | Default       |
|:-----------------------|:-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|:--------------|
| `maintenance.enabled`  | Whether the maintenance period is enabled                                                                                                                                                  | `true`        |
| `maintenance.start`    | Time at which the maintenance window starts in `hh:mm` format (e.g. `23:00`)                                                                                                               | Required `""` |
| `maintenance.duration` | Duration of the maintenance window (e.g. `1h`, `30m`)                                                                                                                                      | Required `""` |
| `maintenance.timezone` | Timezone of the maintenance window format (e.g. `Europe/Amsterdam`).<br />See [List of tz database time zones](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones) for more info | `UTC`         |
| `maintenance.every`    | Days on which the maintenance period applies (e.g. `[Monday, Thursday]`).<br />If left empty, the maintenance window applies every day                                                     | `[]`          |

Here's an example:
```yaml
maintenance:
  start: 23:00
  duration: 1h
  timezone: "Europe/Amsterdam"
  every: [Monday, Thursday]
```
Note that you can also specify each day on separate lines:
```yaml
maintenance:
  start: 23:00
  duration: 1h
  timezone: "Europe/Amsterdam"
  every:
    - Monday
    - Thursday
```
You can also specify maintenance windows on a per-endpoint basis:
```yaml
endpoints:
  - name: endpoint-1
    url: "https://example.org"
    maintenance-windows:
      - start: "07:30"
        duration: 40m
        timezone: "Europe/Berlin"
      - start: "14:30"
        duration: 1h
        timezone: "Europe/Berlin"
```


### Security
| Parameter        | Description                  | Default |
|:-----------------|:-----------------------------|:--------|
| `security`       | Security configuration       | `{}`    |
| `security.basic` | HTTP Basic configuration     | `{}`    |
| `security.oidc`  | OpenID Connect configuration | `{}`    |


#### Basic Authentication
| Parameter                               | Description                                                                        | Default       |
|:----------------------------------------|:-----------------------------------------------------------------------------------|:--------------|
| `security.basic`                        | HTTP Basic configuration                                                           | `{}`          |
| `security.basic.username`               | Username for Basic authentication.                                                 | Required `""` |
| `security.basic.password-bcrypt-base64` | Password hashed with Bcrypt and then encoded with base64 for Basic authentication. | Required `""` |

The example below will require that you authenticate with the username `john.doe` and the password `hunter2`:
```yaml
security:
  basic:
    username: "john.doe"
    password-bcrypt-base64: "JDJhJDEwJHRiMnRFakxWazZLdXBzRERQazB1TE8vckRLY05Yb1hSdnoxWU0yQ1FaYXZRSW1McmladDYu"
```

> ⚠ Make sure to carefully select the cost of the bcrypt hash. The higher the cost, the longer it takes to compute the hash,
> and basic auth verifies the password against the hash on every request. As of 2023-01-06, I suggest a cost of 9.


#### OIDC
| Parameter                        | Description                                                    | Default       |
|:---------------------------------|:---------------------------------------------------------------|:--------------|
| `security.oidc`                  | OpenID Connect configuration                                   | `{}`          |
| `security.oidc.issuer-url`       | Issuer URL                                                     | Required `""` |
| `security.oidc.redirect-url`     | Redirect URL. Must end with `/authorization-code/callback`     | Required `""` |
| `security.oidc.client-id`        | Client id                                                      | Required `""` |
| `security.oidc.client-secret`    | Client secret                                                  | Required `""` |
| `security.oidc.scopes`           | Scopes to request. The only scope you need is `openid`.        | Required `[]` |
| `security.oidc.allowed-subjects` | List of subjects to allow. If empty, all subjects are allowed. | `[]`          |

```yaml
security:
  oidc:
    issuer-url: "https://example.okta.com"
    redirect-url: "https://status.example.com/authorization-code/callback"
    client-id: "123456789"
    client-secret: "abcdefghijk"
    scopes: ["openid"]
    # You may optionally specify a list of allowed subjects. If this is not specified, all subjects will be allowed.
    #allowed-subjects: ["johndoe@example.com"]
```

Confused? Read [Securing Gatus with OIDC using Auth0](https://twin.sh/articles/56/securing-gatus-with-oidc-using-auth0).


### TLS Encryption
Gatus supports basic encryption with TLS. To enable this, certificate files in PEM format have to be provided.

The example below shows an example configuration which makes gatus respond on port 4443 to HTTPS requests:
```yaml
web:
  port: 4443
  tls:
    certificate-file: "certificate.crt"
    private-key-file: "private.key"
```


### Metrics
To enable metrics, you must set `metrics` to `true`. Doing so will expose Prometheus-friendly metrics at the `/metrics`
endpoint on the same port your application is configured to run on (`web.port`).

| Metric name                                  | Type    | Description                                                                | Labels                          | Relevant endpoint types |
|:---------------------------------------------|:--------|:---------------------------------------------------------------------------|:--------------------------------|:------------------------|
| gatus_results_total                          | counter | Number of results per endpoint per success state                           | key, group, name, type, success | All                     |
| gatus_results_code_total                     | counter | Total number of results by code                                            | key, group, name, type, code    | DNS, HTTP               |
| gatus_results_connected_total                | counter | Total number of results in which a connection was successfully established | key, group, name, type          | All                     |
| gatus_results_duration_seconds               | gauge   | Duration of the request in seconds                                         | key, group, name, type          | All                     |
| gatus_results_certificate_expiration_seconds | gauge   | Number of seconds until the certificate expires                            | key, group, name, type          | HTTP, STARTTLS          |
| gatus_results_endpoint_success               | gauge   | Displays whether or not the endpoint was a success (0 failure, 1 success)  | key, group, name, type          | All                     |

See [examples/docker-compose-grafana-prometheus](.examples/docker-compose-grafana-prometheus) for further documentation as well as an example.

#### Custom Labels

Added a Labels field to the Config and Endpoint structs to support key-value pairs for metrics. Updated the Prometheus metrics initialization to include dynamic labels from the configuration. See the example below:

```yaml
endpoints:
  - name: front-end
    group: core
    url: "https://twin.sh/health"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 150"
    labels:
      environment: staging
```

### Connectivity
| Parameter                       | Description                                | Default       |
|:--------------------------------|:-------------------------------------------|:--------------|
| `connectivity`                  | Connectivity configuration                 | `{}`          |
| `connectivity.checker`          | Connectivity checker configuration         | Required `{}` |
| `connectivity.checker.target`   | Host to use for validating connectivity    | Required `""` |
| `connectivity.checker.interval` | Interval at which to validate connectivity | `1m`          |

While Gatus is used to monitor other services, it is possible for Gatus itself to lose connectivity to the internet.
In order to prevent Gatus from reporting endpoints as unhealthy when Gatus itself is unhealthy, you may configure
Gatus to periodically check for internet connectivity.

All endpoint executions are skipped while the connectivity checker deems connectivity to be down.

```yaml
connectivity:
  checker:
    target: 1.1.1.1:53
    interval: 60s
```


### Remote instances (EXPERIMENTAL)
This feature allows you to retrieve endpoint statuses from a remote Gatus instance.

There are two main use cases for this:
- You have multiple Gatus instances running on different machines, and you wish to visually expose the statuses through a single dashboard
- You have one or more Gatus instances that are not publicly accessible (e.g. behind a firewall), and you wish to retrieve

This is an experimental feature. It may be removed or updated in a breaking manner at any time. Furthermore,
there are known issues with this feature. If you'd like to provide some feedback, please write a comment in [#64](https://github.com/TwiN/gatus/issues/64).
Use at your own risk.

| Parameter                          | Description                                  | Default       |
|:-----------------------------------|:---------------------------------------------|:--------------|
| `remote`                           | Remote configuration                         | `{}`          |
| `remote.instances`                 | List of remote instances                     | Required `[]` |
| `remote.instances.endpoint-prefix` | String to prefix all endpoint names with     | `""`          |
| `remote.instances.url`             | URL from which to retrieve endpoint statuses | Required `""` |

```yaml
remote:
  instances:
    - endpoint-prefix: "status.example.org-"
      url: "https://status.example.org/api/v1/endpoints/statuses"
```


## Deployment
Many examples can be found in the [.examples](.examples) folder, but this section will focus on the most popular ways of deploying Gatus.


### Docker
To run Gatus locally with Docker:
```console
docker run -p 8080:8080 --name gatus twinproduction/gatus
```

Other than using one of the examples provided in the [.examples](.examples) folder, you can also try it out locally by
creating a configuration file, we'll call it `config.yaml` for this example, and running the following
command:
```console
docker run -p 8080:8080 --mount type=bind,source="$(pwd)"/config.yaml,target=/config/config.yaml --name gatus twinproduction/gatus
```

If you're on Windows, replace `"$(pwd)"` by the absolute path to your current directory, e.g.:
```console
docker run -p 8080:8080 --mount type=bind,source=C:/Users/Chris/Desktop/config.yaml,target=/config/config.yaml --name gatus twinproduction/gatus
```

To build the image locally:
```console
docker build . -t twinproduction/gatus
```


### Helm Chart
[Helm](https://helm.sh) must be installed to use the chart.
Please refer to Helm's [documentation](https://helm.sh/docs/) to get started.

Once Helm is set up properly, add the repository as follows:

```console
helm repo add twin https://twin.github.io/helm-charts
helm repo update
helm install gatus twin/gatus
```

To get more details, please check [chart's configuration](https://github.com/TwiN/helm-charts/blob/master/charts/gatus/README.md).


### Terraform
Gatus can be deployed on Terraform by using the following module: [terraform-kubernetes-gatus](https://github.com/TwiN/terraform-kubernetes-gatus).


## Running the tests
```console
go test -v ./...
```


## Using in Production
See the [Deployment](#deployment) section.


## FAQ
### Sending a GraphQL request
By setting `endpoints[].graphql` to true, the body will automatically be wrapped by the standard GraphQL `query` parameter.

For instance, the following configuration:
```yaml
endpoints:
  - name: filter-users-by-gender
    url: http://localhost:8080/playground
    method: POST
    graphql: true
    body: |
      {
        users(gender: "female") {
          id
          name
          gender
          avatar
        }
      }
    conditions:
      - "[STATUS] == 200"
      - "[BODY].data.users[0].gender == female"
```

will send a `POST` request to `http://localhost:8080/playground` with the following body:
```json
{"query":"      {\n        users(gender: \"female\") {\n          id\n          name\n          gender\n          avatar\n        }\n      }"}
```


### Recommended interval
> 📝 This does not apply if `disable-monitoring-lock` is set to `true`, as the monitoring lock is what
> tells Gatus to only evaluate one endpoint at a time.

To ensure that Gatus provides reliable and accurate results (i.e. response time), Gatus only evaluates one endpoint at a time
In other words, even if you have multiple endpoints with the same interval, they will not execute at the same time.

You can test this yourself by running Gatus with several endpoints configured with a very short, unrealistic interval,
such as 1ms. You'll notice that the response time does not fluctuate - that is because while endpoints are evaluated on
different goroutines, there's a global lock that prevents multiple endpoints from running at the same time.

Unfortunately, there is a drawback. If you have a lot of endpoints, including some that are very slow or prone to timing out
(the default timeout is 10s), then it means that for the entire duration of the request, no other endpoint can be evaluated.

The interval does not include the duration of the request itself, which means that if an endpoint has an interval of 30s
and the request takes 2s to complete, the timestamp between two evaluations will be 32s, not 30s.

While this does not prevent Gatus' from performing health checks on all other endpoints, it may cause Gatus to be unable
to respect the configured interval, for instance:
- Endpoint A has an interval of 5s, and times out after 10s to complete
- Endpoint B has an interval of 5s, and takes 1ms to complete
- Endpoint B will be unable to run every 5s, because endpoint A's health evaluation takes longer than its interval

To sum it up, while Gatus can handle any interval you throw at it, you're better off having slow requests with
higher interval.

As a rule of thumb, I personally set the interval for more complex health checks to `5m` (5 minutes) and
simple health checks used for alerting (PagerDuty/Twilio) to `30s`.


### Default timeouts
| Endpoint type | Timeout |
|:--------------|:--------|
| HTTP          | 10s     |
| TCP           | 10s     |
| ICMP          | 10s     |

To modify the timeout, see [Client configuration](#client-configuration).


### Monitoring a TCP endpoint
By prefixing `endpoints[].url` with `tcp://`, you can monitor TCP endpoints at a very basic level:
```yaml
endpoints:
  - name: redis
    url: "tcp://127.0.0.1:6379"
    interval: 30s
    conditions:
      - "[CONNECTED] == true"
```
If `endpoints[].body` is set then it is sent and the first 1024 bytes of the response will be in `[BODY]`.

Placeholder `[STATUS]` as well as the fields `endpoints[].headers`,
`endpoints[].method` and `endpoints[].graphql` are not supported for TCP endpoints.

This works for applications such as databases (Postgres, MySQL, etc.) and caches (Redis, Memcached, etc.).

> 📝 `[CONNECTED] == true` does not guarantee that the endpoint itself is healthy - it only guarantees that there's
> something at the given address listening to the given port, and that a connection to that address was successfully
> established.


### Monitoring a UDP endpoint
By prefixing `endpoints[].url` with `udp://`, you can monitor UDP endpoints at a very basic level:
```yaml
endpoints:
  - name: example
    url: "udp://example.org:80"
    conditions:
      - "[CONNECTED] == true"
```

If `endpoints[].body` is set then it is sent and the first 1024 bytes of the response will be in `[BODY]`.

Placeholder `[STATUS]` as well as the fields `endpoints[].headers`,
`endpoints[].method` and `endpoints[].graphql` are not supported for UDP endpoints.

This works for UDP based application.


### Monitoring a SCTP endpoint
By prefixing `endpoints[].url` with `sctp://`, you can monitor Stream Control Transmission Protocol (SCTP) endpoints at a very basic level:
```yaml
endpoints:
  - name: example
    url: "sctp://127.0.0.1:38412"
    conditions:
      - "[CONNECTED] == true"
```

Placeholders `[STATUS]` and `[BODY]` as well as the fields `endpoints[].body`, `endpoints[].headers`,
`endpoints[].method` and `endpoints[].graphql` are not supported for SCTP endpoints.

This works for SCTP based application.


### Monitoring a WebSocket endpoint
By prefixing `endpoints[].url` with `ws://` or `wss://`, you can monitor WebSocket endpoints at a very basic level:
```yaml
endpoints:
  - name: example
    url: "wss://example.com/"
    body: "status"
    conditions:
      - "[CONNECTED] == true"
      - "[BODY].result >= 0"
```

The `[BODY]` placeholder contains the output of the query, and `[CONNECTED]`
shows whether the connection was successfully established. You can use Go template 
syntax. The functions LocalAddr and RandomString with a length can be used.


### Monitoring an endpoint using ICMP
By prefixing `endpoints[].url` with `icmp://`, you can monitor endpoints at a very basic level using ICMP, or more
commonly known as "ping" or "echo":
```yaml
endpoints:
  - name: ping-example
    url: "icmp://example.com"
    conditions:
      - "[CONNECTED] == true"
```

Only the placeholders `[CONNECTED]`, `[IP]` and `[RESPONSE_TIME]` are supported for endpoints of type ICMP.
You can specify a domain prefixed by `icmp://`, or an IP address prefixed by `icmp://`.

If you run Gatus on Linux, please read the Linux section on https://github.com/prometheus-community/pro-bing#linux
if you encounter any problems.


### Monitoring an endpoint using DNS queries
Defining a `dns` configuration in an endpoint will automatically mark said endpoint as an endpoint of type DNS:
```yaml
endpoints:
  - name: example-dns-query
    url: "8.8.8.8" # Address of the DNS server to use
    dns:
      query-name: "example.com"
      query-type: "A"
    conditions:
      - "[BODY] == 93.184.215.14"
      - "[DNS_RCODE] == NOERROR"
```

There are two placeholders that can be used in the conditions for endpoints of type DNS:
- The placeholder `[BODY]` resolves to the output of the query. For instance, a query of type `A` would return an IPv4.
- The placeholder `[DNS_RCODE]` resolves to the name associated to the response code returned by the query, such as
`NOERROR`, `FORMERR`, `SERVFAIL`, `NXDOMAIN`, etc.


### Monitoring an endpoint using SSH
You can monitor endpoints using SSH by prefixing `endpoints[].url` with `ssh://`:
```yaml
endpoints:
  - name: ssh-example
    url: "ssh://example.com:22" # port is optional. Default is 22.
    ssh:
      username: "username"
      password: "password"
    body: |
      {
        "command": "uptime"
      }
    interval: 1m
    conditions:
      - "[CONNECTED] == true"
      - "[STATUS] == 0"
```

you can also use no authentication to monitor the endpoint by not specifying the username
and password fields.

```yaml
endpoints:
  - name: ssh-example
    url: "ssh://example.com:22" # port is optional. Default is 22.
    ssh:
      username: ""
      password: ""

    interval: 1m
    conditions:
      - "[CONNECTED] == true"
      - "[STATUS] == 0"
```

The following placeholders are supported for endpoints of type SSH:
- `[CONNECTED]` resolves to `true` if the SSH connection was successful, `false` otherwise
- `[STATUS]` resolves the exit code of the command executed on the remote server (e.g. `0` for success)


### Monitoring an endpoint using STARTTLS
If you have an email server that you want to ensure there are no problems with, monitoring it through STARTTLS
will serve as a good initial indicator:
```yaml
endpoints:
  - name: starttls-smtp-example
    url: "starttls://smtp.gmail.com:587"
    interval: 30m
    client:
      timeout: 5s
    conditions:
      - "[CONNECTED] == true"
      - "[CERTIFICATE_EXPIRATION] > 48h"
```


### Monitoring an endpoint using TLS
Monitoring endpoints using SSL/TLS encryption, such as LDAP over TLS, can help detect certificate expiration:
```yaml
endpoints:
  - name: tls-ldaps-example
    url: "tls://ldap.example.com:636"
    interval: 30m
    client:
      timeout: 5s
    conditions:
      - "[CONNECTED] == true"
      - "[CERTIFICATE_EXPIRATION] > 48h"
```

If `endpoints[].body` is set then it is sent and the first 1024 bytes of the response will be in `[BODY]`.

Placeholder `[STATUS]` as well as the fields `endpoints[].headers`,
`endpoints[].method` and `endpoints[].graphql` are not supported for TLS endpoints.


### Monitoring domain expiration
You can monitor the expiration of a domain with all endpoint types except for DNS by using the `[DOMAIN_EXPIRATION]`
placeholder:
```yaml
endpoints:
  - name: check-domain-and-certificate-expiration
    url: "https://example.org"
    interval: 1h
    conditions:
      - "[DOMAIN_EXPIRATION] > 720h"
      - "[CERTIFICATE_EXPIRATION] > 240h"
```

> ⚠ The usage of the `[DOMAIN_EXPIRATION]` placeholder requires Gatus to send a request to the official IANA WHOIS service [through a library](https://github.com/TwiN/whois)
> and in some cases, a secondary request to a TLD-specific WHOIS server (e.g. `whois.nic.sh`).
> To prevent the WHOIS service from throttling your IP address if you send too many requests, Gatus will prevent you from
> using the `[DOMAIN_EXPIRATION]` placeholder on an endpoint with an interval of less than `5m`.


### disable-monitoring-lock
Setting `disable-monitoring-lock` to `true` means that multiple endpoints could be monitored at the same time (i.e. parallel execution).

While this behavior wouldn't generally be harmful, conditions using the `[RESPONSE_TIME]` placeholder could be impacted
by the evaluation of multiple endpoints at the same time, therefore, the default value for this parameter is `false`.

There are three main reasons why you might want to disable the monitoring lock:
- You're using Gatus for load testing (each endpoint are periodically evaluated on a different goroutine, so
technically, if you create 100 endpoints with a 1 seconds interval, Gatus will send 100 requests per second)
- You have a _lot_ of endpoints to monitor
- You want to test multiple endpoints at very short intervals (< 5s)


### Reloading configuration on the fly
For the sake of convenience, Gatus automatically reloads the configuration on the fly if the loaded configuration file
is updated while Gatus is running.

By default, the application will exit if the updating configuration is invalid, but you can configure
Gatus to continue running if the configuration file is updated with an invalid configuration by
setting `skip-invalid-config-update` to `true`.

Keep in mind that it is in your best interest to ensure the validity of the configuration file after each update you
apply to the configuration file while Gatus is running by looking at the log and making sure that you do not see the
following message:
```
The configuration file was updated, but it is not valid. The old configuration will continue being used.
```
Failure to do so may result in Gatus being unable to start if the application is restarted for whatever reason.

I recommend not setting `skip-invalid-config-update` to `true` to avoid a situation like this, but the choice is yours
to make.

**If you are not using a file storage**, updating the configuration while Gatus is running is effectively
the same as restarting the application.

> 📝 Updates may not be detected if the config file is bound instead of the config folder. See [#151](https://github.com/TwiN/gatus/issues/151).


### Endpoint groups
Endpoint groups are used for grouping multiple endpoints together on the dashboard.

```yaml
endpoints:
  - name: frontend
    group: core
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"

  - name: backend
    group: core
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"

  - name: monitoring
    group: internal
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"

  - name: nas
    group: internal
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"

  - name: random endpoint that is not part of a group
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
```

The configuration above will result in a dashboard that looks like this:

![Gatus Endpoint Groups](.github/assets/endpoint-groups.png)


### Exposing Gatus on a custom path
Currently, you can expose the Gatus UI using a fully qualified domain name (FQDN) such as `status.example.org`. However, it does not support path-based routing, which means you cannot expose it through a URL like `example.org/status/`.

For more information, see https://github.com/TwiN/gatus/issues/88.


### Exposing Gatus on a custom port
By default, Gatus is exposed on port `8080`, but you may specify a different port by setting the `web.port` parameter:
```yaml
web:
  port: 8081
```

If you're using a PaaS like Heroku that doesn't let you set a custom port and exposes it through an environment
variable instead, you can use that environment variable directly in the configuration file:
```yaml
web:
  port: ${PORT}
```


### Configuring a startup delay
If, for any reason, you need Gatus to wait for a given amount of time before monitoring the endpoints on application start, you can use the `GATUS_DELAY_START_SECONDS` environment variable to make Gatus sleep on startup.


### Keeping your configuration small
While not specific to Gatus, you can leverage YAML anchors to create a default configuration.
If you have a large configuration file, this should help you keep things clean.

<details>
  <summary>Example</summary>

```yaml
default-endpoint: &defaults
  group: core
  interval: 5m
  client:
    insecure: true
    timeout: 30s
  conditions:
    - "[STATUS] == 200"

endpoints:
  - name: anchor-example-1
    <<: *defaults               # This will merge the configuration under &defaults with this endpoint
    url: "https://example.org"

  - name: anchor-example-2
    <<: *defaults
    group: example              # This will override the group defined in &defaults
    url: "https://example.com"

  - name: anchor-example-3
    <<: *defaults
    url: "https://twin.sh/health"
    conditions:                # This will override the conditions defined in &defaults
      - "[STATUS] == 200"
      - "[BODY].status == UP"
```
</details>


### Proxy client configuration
You can configure a proxy for the client to use by setting the `proxy-url` parameter in the client configuration.

```yaml
endpoints:
  - name: website
    url: "https://twin.sh/health"
    client:
      proxy-url: http://proxy.example.com:8080
    conditions:
      - "[STATUS] == 200"
```


### How to fix 431 Request Header Fields Too Large error
Depending on where your environment is deployed and what kind of middleware or reverse proxy sits in front of Gatus,
you may run into this issue. This could be because the request headers are too large, e.g. big cookies.

By default, `web.read-buffer-size` is set to `8192`, but increasing this value like so will increase the read buffer size:
```yaml
web:
  read-buffer-size: 32768
```


### Badges
#### Uptime
![Uptime 1h](https://status.twin.sh/api/v1/endpoints/core_blog-external/uptimes/1h/badge.svg)
![Uptime 24h](https://status.twin.sh/api/v1/endpoints/core_blog-external/uptimes/24h/badge.svg)
![Uptime 7d](https://status.twin.sh/api/v1/endpoints/core_blog-external/uptimes/7d/badge.svg)
![Uptime 30d](https://status.twin.sh/api/v1/endpoints/core_blog-external/uptimes/30d/badge.svg)

Gatus can automatically generate an SVG badge for one of your monitored endpoints.
This allows you to put badges in your individual applications' README or even create your own status page if you
desire.

The path to generate a badge is the following:
```
/api/v1/endpoints/{key}/uptimes/{duration}/badge.svg
```
Where:
- `{duration}` is `30d`, `7d`, `24h` or `1h`
- `{key}` has the pattern `<GROUP_NAME>_<ENDPOINT_NAME>` in which both variables have ` `, `/`, `_`, `,`, `.` and `#` replaced by `-`.

For instance, if you want the uptime during the last 24 hours from the endpoint `frontend` in the group `core`,
the URL would look like this:
```
https://example.com/api/v1/endpoints/core_frontend/uptimes/7d/badge.svg
```
If you want to display an endpoint that is not part of a group, you must leave the group value empty:
```
https://example.com/api/v1/endpoints/_frontend/uptimes/7d/badge.svg
```
Example:
```
![Uptime 24h](https://status.twin.sh/api/v1/endpoints/core_blog-external/uptimes/24h/badge.svg)
```
If you'd like to see a visual example of each badge available, you can simply navigate to the endpoint's detail page.


#### Health
![Health](https://status.twin.sh/api/v1/endpoints/core_blog-external/health/badge.svg)

The path to generate a badge is the following:
```
/api/v1/endpoints/{key}/health/badge.svg
```
Where:
- `{key}` has the pattern `<GROUP_NAME>_<ENDPOINT_NAME>` in which both variables have ` `, `/`, `_`, `,`, `.` and `#` replaced by `-`.

For instance, if you want the current status of the endpoint `frontend` in the group `core`,
the URL would look like this:
```
https://example.com/api/v1/endpoints/core_frontend/health/badge.svg
```


#### Health (Shields.io)
![Health](https://img.shields.io/endpoint?url=https%3A%2F%2Fstatus.twin.sh%2Fapi%2Fv1%2Fendpoints%2Fcore_blog-external%2Fhealth%2Fbadge.shields)

The path to generate a badge is the following:
```
/api/v1/endpoints/{key}/health/badge.shields
```
Where:
- `{key}` has the pattern `<GROUP_NAME>_<ENDPOINT_NAME>` in which both variables have ` `, `/`, `_`, `,`, `.` and `#` replaced by `-`.

For instance, if you want the current status of the endpoint `frontend` in the group `core`,
the URL would look like this:
```
https://example.com/api/v1/endpoints/core_frontend/health/badge.shields
```

See more information about the Shields.io badge endpoint [here](https://shields.io/badges/endpoint-badge).


#### Response time
![Response time 1h](https://status.twin.sh/api/v1/endpoints/core_blog-external/response-times/1h/badge.svg)
![Response time 24h](https://status.twin.sh/api/v1/endpoints/core_blog-external/response-times/24h/badge.svg)
![Response time 7d](https://status.twin.sh/api/v1/endpoints/core_blog-external/response-times/7d/badge.svg)
![Response time 30d](https://status.twin.sh/api/v1/endpoints/core_blog-external/response-times/30d/badge.svg)

The endpoint to generate a badge is the following:
```
/api/v1/endpoints/{key}/response-times/{duration}/badge.svg
```
Where:
- `{duration}` is `30d`, `7d`, `24h` or `1h`
- `{key}` has the pattern `<GROUP_NAME>_<ENDPOINT_NAME>` in which both variables have ` `, `/`, `_`, `,`, `.` and `#` replaced by `-`.

#### Response time (chart)
![Response time 24h](https://status.twin.sh/api/v1/endpoints/core_blog-external/response-times/24h/chart.svg)
![Response time 7d](https://status.twin.sh/api/v1/endpoints/core_blog-external/response-times/7d/chart.svg)
![Response time 30d](https://status.twin.sh/api/v1/endpoints/core_blog-external/response-times/30d/chart.svg)

The endpoint to generate a response time chart is the following:
```
/api/v1/endpoints/{key}/response-times/{duration}/chart.svg
```
Where:
- `{duration}` is `30d`, `7d`, or `24h`
- `{key}` has the pattern `<GROUP_NAME>_<ENDPOINT_NAME>` in which both variables have ` `, `/`, `_`, `,`, `.` and `#` replaced by `-`.

##### How to change the color thresholds of the response time badge
To change the response time badges' threshold, a corresponding configuration can be added to an endpoint.
The values in the array correspond to the levels [Awesome, Great, Good, Passable, Bad]
All five values must be given in milliseconds (ms).

```yaml
endpoints:
- name: nas
  group: internal
  url: "https://example.org/"
  interval: 5m
  conditions:
    - "[STATUS] == 200"
  ui:
    badge:
      response-time:
        thresholds: [550, 850, 1350, 1650, 1750]
```


### API
Gatus provides a simple read-only API that can be queried in order to programmatically determine endpoint status and history.

All endpoints are available via a GET request to the following endpoint:
```
/api/v1/endpoints/statuses
````
Example: https://status.twin.sh/api/v1/endpoints/statuses

Specific endpoints can also be queried by using the following pattern:
```
/api/v1/endpoints/{group}_{endpoint}/statuses
```
Example: https://status.twin.sh/api/v1/endpoints/core_blog-home/statuses

Gzip compression will be used if the `Accept-Encoding` HTTP header contains `gzip`.

The API will return a JSON payload with the `Content-Type` response header set to `application/json`.
No such header is required to query the API.


#### Interacting with the API programmatically
See [TwiN/gatus-sdk](https://github.com/TwiN/gatus-sdk)


#### Raw Data
Gatus exposes the raw data for one of your monitored endpoints.
This allows you to track and aggregate data in your own applications for monitored endpoints. For instance if you want to track uptime for a period longer than 7 days.

##### Uptime
The path to get raw uptime data for an endpoint is:
```
/api/v1/endpoints/{key}/uptimes/{duration}
```
Where:
- `{duration}` is `30d`, `7d`, `24h` or `1h`
- `{key}` has the pattern `<GROUP_NAME>_<ENDPOINT_NAME>` in which both variables have ` `, `/`, `_`, `,`, `.` and `#` replaced by `-`.

For instance, if you want the raw uptime data for the last 24 hours from the endpoint `frontend` in the group `core`, the URL would look like this:
```
https://example.com/api/v1/endpoints/core_frontend/uptimes/24h
```

##### Response Time
The path to get raw response time data for an endpoint is:
```
/api/v1/endpoints/{key}/response-times/{duration}
```
Where:
- `{duration}` is `30d`, `7d`, `24h` or `1h`
- `{key}` has the pattern `<GROUP_NAME>_<ENDPOINT_NAME>` in which both variables have ` `, `/`, `_`, `,`, `.` and `#` replaced by `-`.

For instance, if you want the raw response time data for the last 24 hours from the endpoint `frontend` in the group `core`, the URL would look like this:
```
https://example.com/api/v1/endpoints/core_frontend/response-times/24h
```


### Installing as binary
You can download Gatus as a binary using the following command:
```
go install github.com/TwiN/gatus/v5@latest
```


### High level design overview
![Gatus diagram](.github/assets/gatus-diagram.jpg)
